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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * net/sched/sch_api.c Packet scheduler API.
4 *
5 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
6 *
7 * Fixes:
8 *
9 * Rani Assaf <rani@magic.metawire.com> :980802: JIFFIES and CPU clock sources are repaired.
10 * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
11 * Jamal Hadi Salim <hadi@nortelnetworks.com>: 990601: ingress support
12 */
13
14#include <linux/module.h>
15#include <linux/types.h>
16#include <linux/kernel.h>
17#include <linux/string.h>
18#include <linux/errno.h>
19#include <linux/skbuff.h>
20#include <linux/init.h>
21#include <linux/proc_fs.h>
22#include <linux/seq_file.h>
23#include <linux/kmod.h>
24#include <linux/list.h>
25#include <linux/hrtimer.h>
26#include <linux/slab.h>
27#include <linux/hashtable.h>
28
29#include <net/net_namespace.h>
30#include <net/sock.h>
31#include <net/netlink.h>
32#include <net/pkt_sched.h>
33#include <net/pkt_cls.h>
34#include <net/tc_wrapper.h>
35
36#include <trace/events/qdisc.h>
37
38/*
39
40 Short review.
41 -------------
42
43 This file consists of two interrelated parts:
44
45 1. queueing disciplines manager frontend.
46 2. traffic classes manager frontend.
47
48 Generally, queueing discipline ("qdisc") is a black box,
49 which is able to enqueue packets and to dequeue them (when
50 device is ready to send something) in order and at times
51 determined by algorithm hidden in it.
52
53 qdisc's are divided to two categories:
54 - "queues", which have no internal structure visible from outside.
55 - "schedulers", which split all the packets to "traffic classes",
56 using "packet classifiers" (look at cls_api.c)
57
58 In turn, classes may have child qdiscs (as rule, queues)
59 attached to them etc. etc. etc.
60
61 The goal of the routines in this file is to translate
62 information supplied by user in the form of handles
63 to more intelligible for kernel form, to make some sanity
64 checks and part of work, which is common to all qdiscs
65 and to provide rtnetlink notifications.
66
67 All real intelligent work is done inside qdisc modules.
68
69
70
71 Every discipline has two major routines: enqueue and dequeue.
72
73 ---dequeue
74
75 dequeue usually returns a skb to send. It is allowed to return NULL,
76 but it does not mean that queue is empty, it just means that
77 discipline does not want to send anything this time.
78 Queue is really empty if q->q.qlen == 0.
79 For complicated disciplines with multiple queues q->q is not
80 real packet queue, but however q->q.qlen must be valid.
81
82 ---enqueue
83
84 enqueue returns 0, if packet was enqueued successfully.
85 If packet (this one or another one) was dropped, it returns
86 not zero error code.
87 NET_XMIT_DROP - this packet dropped
88 Expected action: do not backoff, but wait until queue will clear.
89 NET_XMIT_CN - probably this packet enqueued, but another one dropped.
90 Expected action: backoff or ignore
91
92 Auxiliary routines:
93
94 ---peek
95
96 like dequeue but without removing a packet from the queue
97
98 ---reset
99
100 returns qdisc to initial state: purge all buffers, clear all
101 timers, counters (except for statistics) etc.
102
103 ---init
104
105 initializes newly created qdisc.
106
107 ---destroy
108
109 destroys resources allocated by init and during lifetime of qdisc.
110
111 ---change
112
113 changes qdisc parameters.
114 */
115
116/* Protects list of registered TC modules. It is pure SMP lock. */
117static DEFINE_RWLOCK(qdisc_mod_lock);
118
119
120/************************************************
121 * Queueing disciplines manipulation. *
122 ************************************************/
123
124
125/* The list of all installed queueing disciplines. */
126
127static struct Qdisc_ops *qdisc_base;
128
129/* Register/unregister queueing discipline */
130
131int register_qdisc(struct Qdisc_ops *qops)
132{
133 struct Qdisc_ops *q, **qp;
134 int rc = -EEXIST;
135
136 write_lock(&qdisc_mod_lock);
137 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
138 if (!strcmp(qops->id, q->id))
139 goto out;
140
141 if (qops->enqueue == NULL)
142 qops->enqueue = noop_qdisc_ops.enqueue;
143 if (qops->peek == NULL) {
144 if (qops->dequeue == NULL)
145 qops->peek = noop_qdisc_ops.peek;
146 else
147 goto out_einval;
148 }
149 if (qops->dequeue == NULL)
150 qops->dequeue = noop_qdisc_ops.dequeue;
151
152 if (qops->cl_ops) {
153 const struct Qdisc_class_ops *cops = qops->cl_ops;
154
155 if (!(cops->find && cops->walk && cops->leaf))
156 goto out_einval;
157
158 if (cops->tcf_block && !(cops->bind_tcf && cops->unbind_tcf))
159 goto out_einval;
160 }
161
162 qops->next = NULL;
163 *qp = qops;
164 rc = 0;
165out:
166 write_unlock(&qdisc_mod_lock);
167 return rc;
168
169out_einval:
170 rc = -EINVAL;
171 goto out;
172}
173EXPORT_SYMBOL(register_qdisc);
174
175void unregister_qdisc(struct Qdisc_ops *qops)
176{
177 struct Qdisc_ops *q, **qp;
178 int err = -ENOENT;
179
180 write_lock(&qdisc_mod_lock);
181 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
182 if (q == qops)
183 break;
184 if (q) {
185 *qp = q->next;
186 q->next = NULL;
187 err = 0;
188 }
189 write_unlock(&qdisc_mod_lock);
190
191 WARN(err, "unregister qdisc(%s) failed\n", qops->id);
192}
193EXPORT_SYMBOL(unregister_qdisc);
194
195/* Get default qdisc if not otherwise specified */
196void qdisc_get_default(char *name, size_t len)
197{
198 read_lock(&qdisc_mod_lock);
199 strscpy(name, default_qdisc_ops->id, len);
200 read_unlock(&qdisc_mod_lock);
201}
202
203static struct Qdisc_ops *qdisc_lookup_default(const char *name)
204{
205 struct Qdisc_ops *q = NULL;
206
207 for (q = qdisc_base; q; q = q->next) {
208 if (!strcmp(name, q->id)) {
209 if (!try_module_get(q->owner))
210 q = NULL;
211 break;
212 }
213 }
214
215 return q;
216}
217
218/* Set new default qdisc to use */
219int qdisc_set_default(const char *name)
220{
221 const struct Qdisc_ops *ops;
222
223 if (!capable(CAP_NET_ADMIN))
224 return -EPERM;
225
226 write_lock(&qdisc_mod_lock);
227 ops = qdisc_lookup_default(name);
228 if (!ops) {
229 /* Not found, drop lock and try to load module */
230 write_unlock(&qdisc_mod_lock);
231 request_module(NET_SCH_ALIAS_PREFIX "%s", name);
232 write_lock(&qdisc_mod_lock);
233
234 ops = qdisc_lookup_default(name);
235 }
236
237 if (ops) {
238 /* Set new default */
239 module_put(default_qdisc_ops->owner);
240 default_qdisc_ops = ops;
241 }
242 write_unlock(&qdisc_mod_lock);
243
244 return ops ? 0 : -ENOENT;
245}
246
247#ifdef CONFIG_NET_SCH_DEFAULT
248/* Set default value from kernel config */
249static int __init sch_default_qdisc(void)
250{
251 return qdisc_set_default(CONFIG_DEFAULT_NET_SCH);
252}
253late_initcall(sch_default_qdisc);
254#endif
255
256/* We know handle. Find qdisc among all qdisc's attached to device
257 * (root qdisc, all its children, children of children etc.)
258 * Note: caller either uses rtnl or rcu_read_lock()
259 */
260
261static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle)
262{
263 struct Qdisc *q;
264
265 if (!qdisc_dev(root))
266 return (root->handle == handle ? root : NULL);
267
268 if (!(root->flags & TCQ_F_BUILTIN) &&
269 root->handle == handle)
270 return root;
271
272 hash_for_each_possible_rcu(qdisc_dev(root)->qdisc_hash, q, hash, handle,
273 lockdep_rtnl_is_held()) {
274 if (q->handle == handle)
275 return q;
276 }
277 return NULL;
278}
279
280void qdisc_hash_add(struct Qdisc *q, bool invisible)
281{
282 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
283 ASSERT_RTNL();
284 hash_add_rcu(qdisc_dev(q)->qdisc_hash, &q->hash, q->handle);
285 if (invisible)
286 q->flags |= TCQ_F_INVISIBLE;
287 }
288}
289EXPORT_SYMBOL(qdisc_hash_add);
290
291void qdisc_hash_del(struct Qdisc *q)
292{
293 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
294 ASSERT_RTNL();
295 hash_del_rcu(&q->hash);
296 }
297}
298EXPORT_SYMBOL(qdisc_hash_del);
299
300struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
301{
302 struct Qdisc *q;
303
304 if (!handle)
305 return NULL;
306 q = qdisc_match_from_root(rtnl_dereference(dev->qdisc), handle);
307 if (q)
308 goto out;
309
310 if (dev_ingress_queue(dev))
311 q = qdisc_match_from_root(
312 rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping),
313 handle);
314out:
315 return q;
316}
317
318struct Qdisc *qdisc_lookup_rcu(struct net_device *dev, u32 handle)
319{
320 struct netdev_queue *nq;
321 struct Qdisc *q;
322
323 if (!handle)
324 return NULL;
325 q = qdisc_match_from_root(rcu_dereference(dev->qdisc), handle);
326 if (q)
327 goto out;
328
329 nq = dev_ingress_queue_rcu(dev);
330 if (nq)
331 q = qdisc_match_from_root(rcu_dereference(nq->qdisc_sleeping),
332 handle);
333out:
334 return q;
335}
336
337static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
338{
339 unsigned long cl;
340 const struct Qdisc_class_ops *cops = p->ops->cl_ops;
341
342 if (cops == NULL)
343 return NULL;
344 cl = cops->find(p, classid);
345
346 if (cl == 0)
347 return NULL;
348 return cops->leaf(p, cl);
349}
350
351/* Find queueing discipline by name */
352
353static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind)
354{
355 struct Qdisc_ops *q = NULL;
356
357 if (kind) {
358 read_lock(&qdisc_mod_lock);
359 for (q = qdisc_base; q; q = q->next) {
360 if (nla_strcmp(kind, q->id) == 0) {
361 if (!try_module_get(q->owner))
362 q = NULL;
363 break;
364 }
365 }
366 read_unlock(&qdisc_mod_lock);
367 }
368 return q;
369}
370
371/* The linklayer setting were not transferred from iproute2, in older
372 * versions, and the rate tables lookup systems have been dropped in
373 * the kernel. To keep backward compatible with older iproute2 tc
374 * utils, we detect the linklayer setting by detecting if the rate
375 * table were modified.
376 *
377 * For linklayer ATM table entries, the rate table will be aligned to
378 * 48 bytes, thus some table entries will contain the same value. The
379 * mpu (min packet unit) is also encoded into the old rate table, thus
380 * starting from the mpu, we find low and high table entries for
381 * mapping this cell. If these entries contain the same value, when
382 * the rate tables have been modified for linklayer ATM.
383 *
384 * This is done by rounding mpu to the nearest 48 bytes cell/entry,
385 * and then roundup to the next cell, calc the table entry one below,
386 * and compare.
387 */
388static __u8 __detect_linklayer(struct tc_ratespec *r, __u32 *rtab)
389{
390 int low = roundup(r->mpu, 48);
391 int high = roundup(low+1, 48);
392 int cell_low = low >> r->cell_log;
393 int cell_high = (high >> r->cell_log) - 1;
394
395 /* rtab is too inaccurate at rates > 100Mbit/s */
396 if ((r->rate > (100000000/8)) || (rtab[0] == 0)) {
397 pr_debug("TC linklayer: Giving up ATM detection\n");
398 return TC_LINKLAYER_ETHERNET;
399 }
400
401 if ((cell_high > cell_low) && (cell_high < 256)
402 && (rtab[cell_low] == rtab[cell_high])) {
403 pr_debug("TC linklayer: Detected ATM, low(%d)=high(%d)=%u\n",
404 cell_low, cell_high, rtab[cell_high]);
405 return TC_LINKLAYER_ATM;
406 }
407 return TC_LINKLAYER_ETHERNET;
408}
409
410static struct qdisc_rate_table *qdisc_rtab_list;
411
412struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
413 struct nlattr *tab,
414 struct netlink_ext_ack *extack)
415{
416 struct qdisc_rate_table *rtab;
417
418 if (tab == NULL || r->rate == 0 ||
419 r->cell_log == 0 || r->cell_log >= 32 ||
420 nla_len(tab) != TC_RTAB_SIZE) {
421 NL_SET_ERR_MSG(extack, "Invalid rate table parameters for searching");
422 return NULL;
423 }
424
425 for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) {
426 if (!memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) &&
427 !memcmp(&rtab->data, nla_data(tab), 1024)) {
428 rtab->refcnt++;
429 return rtab;
430 }
431 }
432
433 rtab = kmalloc(sizeof(*rtab), GFP_KERNEL);
434 if (rtab) {
435 rtab->rate = *r;
436 rtab->refcnt = 1;
437 memcpy(rtab->data, nla_data(tab), 1024);
438 if (r->linklayer == TC_LINKLAYER_UNAWARE)
439 r->linklayer = __detect_linklayer(r, rtab->data);
440 rtab->next = qdisc_rtab_list;
441 qdisc_rtab_list = rtab;
442 } else {
443 NL_SET_ERR_MSG(extack, "Failed to allocate new qdisc rate table");
444 }
445 return rtab;
446}
447EXPORT_SYMBOL(qdisc_get_rtab);
448
449void qdisc_put_rtab(struct qdisc_rate_table *tab)
450{
451 struct qdisc_rate_table *rtab, **rtabp;
452
453 if (!tab || --tab->refcnt)
454 return;
455
456 for (rtabp = &qdisc_rtab_list;
457 (rtab = *rtabp) != NULL;
458 rtabp = &rtab->next) {
459 if (rtab == tab) {
460 *rtabp = rtab->next;
461 kfree(rtab);
462 return;
463 }
464 }
465}
466EXPORT_SYMBOL(qdisc_put_rtab);
467
468static LIST_HEAD(qdisc_stab_list);
469
470static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = {
471 [TCA_STAB_BASE] = { .len = sizeof(struct tc_sizespec) },
472 [TCA_STAB_DATA] = { .type = NLA_BINARY },
473};
474
475static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt,
476 struct netlink_ext_ack *extack)
477{
478 struct nlattr *tb[TCA_STAB_MAX + 1];
479 struct qdisc_size_table *stab;
480 struct tc_sizespec *s;
481 unsigned int tsize = 0;
482 u16 *tab = NULL;
483 int err;
484
485 err = nla_parse_nested_deprecated(tb, TCA_STAB_MAX, opt, stab_policy,
486 extack);
487 if (err < 0)
488 return ERR_PTR(err);
489 if (!tb[TCA_STAB_BASE]) {
490 NL_SET_ERR_MSG(extack, "Size table base attribute is missing");
491 return ERR_PTR(-EINVAL);
492 }
493
494 s = nla_data(tb[TCA_STAB_BASE]);
495
496 if (s->tsize > 0) {
497 if (!tb[TCA_STAB_DATA]) {
498 NL_SET_ERR_MSG(extack, "Size table data attribute is missing");
499 return ERR_PTR(-EINVAL);
500 }
501 tab = nla_data(tb[TCA_STAB_DATA]);
502 tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16);
503 }
504
505 if (tsize != s->tsize || (!tab && tsize > 0)) {
506 NL_SET_ERR_MSG(extack, "Invalid size of size table");
507 return ERR_PTR(-EINVAL);
508 }
509
510 list_for_each_entry(stab, &qdisc_stab_list, list) {
511 if (memcmp(&stab->szopts, s, sizeof(*s)))
512 continue;
513 if (tsize > 0 &&
514 memcmp(stab->data, tab, flex_array_size(stab, data, tsize)))
515 continue;
516 stab->refcnt++;
517 return stab;
518 }
519
520 if (s->size_log > STAB_SIZE_LOG_MAX ||
521 s->cell_log > STAB_SIZE_LOG_MAX) {
522 NL_SET_ERR_MSG(extack, "Invalid logarithmic size of size table");
523 return ERR_PTR(-EINVAL);
524 }
525
526 stab = kmalloc(struct_size(stab, data, tsize), GFP_KERNEL);
527 if (!stab)
528 return ERR_PTR(-ENOMEM);
529
530 stab->refcnt = 1;
531 stab->szopts = *s;
532 if (tsize > 0)
533 memcpy(stab->data, tab, flex_array_size(stab, data, tsize));
534
535 list_add_tail(&stab->list, &qdisc_stab_list);
536
537 return stab;
538}
539
540void qdisc_put_stab(struct qdisc_size_table *tab)
541{
542 if (!tab)
543 return;
544
545 if (--tab->refcnt == 0) {
546 list_del(&tab->list);
547 kfree_rcu(tab, rcu);
548 }
549}
550EXPORT_SYMBOL(qdisc_put_stab);
551
552static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab)
553{
554 struct nlattr *nest;
555
556 nest = nla_nest_start_noflag(skb, TCA_STAB);
557 if (nest == NULL)
558 goto nla_put_failure;
559 if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts))
560 goto nla_put_failure;
561 nla_nest_end(skb, nest);
562
563 return skb->len;
564
565nla_put_failure:
566 return -1;
567}
568
569void __qdisc_calculate_pkt_len(struct sk_buff *skb,
570 const struct qdisc_size_table *stab)
571{
572 int pkt_len, slot;
573
574 pkt_len = skb->len + stab->szopts.overhead;
575 if (unlikely(!stab->szopts.tsize))
576 goto out;
577
578 slot = pkt_len + stab->szopts.cell_align;
579 if (unlikely(slot < 0))
580 slot = 0;
581
582 slot >>= stab->szopts.cell_log;
583 if (likely(slot < stab->szopts.tsize))
584 pkt_len = stab->data[slot];
585 else
586 pkt_len = stab->data[stab->szopts.tsize - 1] *
587 (slot / stab->szopts.tsize) +
588 stab->data[slot % stab->szopts.tsize];
589
590 pkt_len <<= stab->szopts.size_log;
591out:
592 if (unlikely(pkt_len < 1))
593 pkt_len = 1;
594 qdisc_skb_cb(skb)->pkt_len = pkt_len;
595}
596
597void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc)
598{
599 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
600 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n",
601 txt, qdisc->ops->id, qdisc->handle >> 16);
602 qdisc->flags |= TCQ_F_WARN_NONWC;
603 }
604}
605EXPORT_SYMBOL(qdisc_warn_nonwc);
606
607static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
608{
609 struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
610 timer);
611
612 rcu_read_lock();
613 __netif_schedule(qdisc_root(wd->qdisc));
614 rcu_read_unlock();
615
616 return HRTIMER_NORESTART;
617}
618
619void qdisc_watchdog_init_clockid(struct qdisc_watchdog *wd, struct Qdisc *qdisc,
620 clockid_t clockid)
621{
622 hrtimer_init(&wd->timer, clockid, HRTIMER_MODE_ABS_PINNED);
623 wd->timer.function = qdisc_watchdog;
624 wd->qdisc = qdisc;
625}
626EXPORT_SYMBOL(qdisc_watchdog_init_clockid);
627
628void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
629{
630 qdisc_watchdog_init_clockid(wd, qdisc, CLOCK_MONOTONIC);
631}
632EXPORT_SYMBOL(qdisc_watchdog_init);
633
634void qdisc_watchdog_schedule_range_ns(struct qdisc_watchdog *wd, u64 expires,
635 u64 delta_ns)
636{
637 bool deactivated;
638
639 rcu_read_lock();
640 deactivated = test_bit(__QDISC_STATE_DEACTIVATED,
641 &qdisc_root_sleeping(wd->qdisc)->state);
642 rcu_read_unlock();
643 if (deactivated)
644 return;
645
646 if (hrtimer_is_queued(&wd->timer)) {
647 u64 softexpires;
648
649 softexpires = ktime_to_ns(hrtimer_get_softexpires(&wd->timer));
650 /* If timer is already set in [expires, expires + delta_ns],
651 * do not reprogram it.
652 */
653 if (softexpires - expires <= delta_ns)
654 return;
655 }
656
657 hrtimer_start_range_ns(&wd->timer,
658 ns_to_ktime(expires),
659 delta_ns,
660 HRTIMER_MODE_ABS_PINNED);
661}
662EXPORT_SYMBOL(qdisc_watchdog_schedule_range_ns);
663
664void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
665{
666 hrtimer_cancel(&wd->timer);
667}
668EXPORT_SYMBOL(qdisc_watchdog_cancel);
669
670static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
671{
672 struct hlist_head *h;
673 unsigned int i;
674
675 h = kvmalloc_array(n, sizeof(struct hlist_head), GFP_KERNEL);
676
677 if (h != NULL) {
678 for (i = 0; i < n; i++)
679 INIT_HLIST_HEAD(&h[i]);
680 }
681 return h;
682}
683
684void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
685{
686 struct Qdisc_class_common *cl;
687 struct hlist_node *next;
688 struct hlist_head *nhash, *ohash;
689 unsigned int nsize, nmask, osize;
690 unsigned int i, h;
691
692 /* Rehash when load factor exceeds 0.75 */
693 if (clhash->hashelems * 4 <= clhash->hashsize * 3)
694 return;
695 nsize = clhash->hashsize * 2;
696 nmask = nsize - 1;
697 nhash = qdisc_class_hash_alloc(nsize);
698 if (nhash == NULL)
699 return;
700
701 ohash = clhash->hash;
702 osize = clhash->hashsize;
703
704 sch_tree_lock(sch);
705 for (i = 0; i < osize; i++) {
706 hlist_for_each_entry_safe(cl, next, &ohash[i], hnode) {
707 h = qdisc_class_hash(cl->classid, nmask);
708 hlist_add_head(&cl->hnode, &nhash[h]);
709 }
710 }
711 clhash->hash = nhash;
712 clhash->hashsize = nsize;
713 clhash->hashmask = nmask;
714 sch_tree_unlock(sch);
715
716 kvfree(ohash);
717}
718EXPORT_SYMBOL(qdisc_class_hash_grow);
719
720int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
721{
722 unsigned int size = 4;
723
724 clhash->hash = qdisc_class_hash_alloc(size);
725 if (!clhash->hash)
726 return -ENOMEM;
727 clhash->hashsize = size;
728 clhash->hashmask = size - 1;
729 clhash->hashelems = 0;
730 return 0;
731}
732EXPORT_SYMBOL(qdisc_class_hash_init);
733
734void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
735{
736 kvfree(clhash->hash);
737}
738EXPORT_SYMBOL(qdisc_class_hash_destroy);
739
740void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
741 struct Qdisc_class_common *cl)
742{
743 unsigned int h;
744
745 INIT_HLIST_NODE(&cl->hnode);
746 h = qdisc_class_hash(cl->classid, clhash->hashmask);
747 hlist_add_head(&cl->hnode, &clhash->hash[h]);
748 clhash->hashelems++;
749}
750EXPORT_SYMBOL(qdisc_class_hash_insert);
751
752void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
753 struct Qdisc_class_common *cl)
754{
755 hlist_del(&cl->hnode);
756 clhash->hashelems--;
757}
758EXPORT_SYMBOL(qdisc_class_hash_remove);
759
760/* Allocate an unique handle from space managed by kernel
761 * Possible range is [8000-FFFF]:0000 (0x8000 values)
762 */
763static u32 qdisc_alloc_handle(struct net_device *dev)
764{
765 int i = 0x8000;
766 static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
767
768 do {
769 autohandle += TC_H_MAKE(0x10000U, 0);
770 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
771 autohandle = TC_H_MAKE(0x80000000U, 0);
772 if (!qdisc_lookup(dev, autohandle))
773 return autohandle;
774 cond_resched();
775 } while (--i > 0);
776
777 return 0;
778}
779
780void qdisc_tree_reduce_backlog(struct Qdisc *sch, int n, int len)
781{
782 bool qdisc_is_offloaded = sch->flags & TCQ_F_OFFLOADED;
783 const struct Qdisc_class_ops *cops;
784 unsigned long cl;
785 u32 parentid;
786 bool notify;
787 int drops;
788
789 if (n == 0 && len == 0)
790 return;
791 drops = max_t(int, n, 0);
792 rcu_read_lock();
793 while ((parentid = sch->parent)) {
794 if (parentid == TC_H_ROOT)
795 break;
796
797 if (sch->flags & TCQ_F_NOPARENT)
798 break;
799 /* Notify parent qdisc only if child qdisc becomes empty.
800 *
801 * If child was empty even before update then backlog
802 * counter is screwed and we skip notification because
803 * parent class is already passive.
804 *
805 * If the original child was offloaded then it is allowed
806 * to be seem as empty, so the parent is notified anyway.
807 */
808 notify = !sch->q.qlen && !WARN_ON_ONCE(!n &&
809 !qdisc_is_offloaded);
810 /* TODO: perform the search on a per txq basis */
811 sch = qdisc_lookup_rcu(qdisc_dev(sch), TC_H_MAJ(parentid));
812 if (sch == NULL) {
813 WARN_ON_ONCE(parentid != TC_H_ROOT);
814 break;
815 }
816 cops = sch->ops->cl_ops;
817 if (notify && cops->qlen_notify) {
818 cl = cops->find(sch, parentid);
819 cops->qlen_notify(sch, cl);
820 }
821 sch->q.qlen -= n;
822 sch->qstats.backlog -= len;
823 __qdisc_qstats_drop(sch, drops);
824 }
825 rcu_read_unlock();
826}
827EXPORT_SYMBOL(qdisc_tree_reduce_backlog);
828
829int qdisc_offload_dump_helper(struct Qdisc *sch, enum tc_setup_type type,
830 void *type_data)
831{
832 struct net_device *dev = qdisc_dev(sch);
833 int err;
834
835 sch->flags &= ~TCQ_F_OFFLOADED;
836 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
837 return 0;
838
839 err = dev->netdev_ops->ndo_setup_tc(dev, type, type_data);
840 if (err == -EOPNOTSUPP)
841 return 0;
842
843 if (!err)
844 sch->flags |= TCQ_F_OFFLOADED;
845
846 return err;
847}
848EXPORT_SYMBOL(qdisc_offload_dump_helper);
849
850void qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
851 struct Qdisc *new, struct Qdisc *old,
852 enum tc_setup_type type, void *type_data,
853 struct netlink_ext_ack *extack)
854{
855 bool any_qdisc_is_offloaded;
856 int err;
857
858 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
859 return;
860
861 err = dev->netdev_ops->ndo_setup_tc(dev, type, type_data);
862
863 /* Don't report error if the graft is part of destroy operation. */
864 if (!err || !new || new == &noop_qdisc)
865 return;
866
867 /* Don't report error if the parent, the old child and the new
868 * one are not offloaded.
869 */
870 any_qdisc_is_offloaded = new->flags & TCQ_F_OFFLOADED;
871 any_qdisc_is_offloaded |= sch && sch->flags & TCQ_F_OFFLOADED;
872 any_qdisc_is_offloaded |= old && old->flags & TCQ_F_OFFLOADED;
873
874 if (any_qdisc_is_offloaded)
875 NL_SET_ERR_MSG(extack, "Offloading graft operation failed.");
876}
877EXPORT_SYMBOL(qdisc_offload_graft_helper);
878
879void qdisc_offload_query_caps(struct net_device *dev,
880 enum tc_setup_type type,
881 void *caps, size_t caps_len)
882{
883 const struct net_device_ops *ops = dev->netdev_ops;
884 struct tc_query_caps_base base = {
885 .type = type,
886 .caps = caps,
887 };
888
889 memset(caps, 0, caps_len);
890
891 if (ops->ndo_setup_tc)
892 ops->ndo_setup_tc(dev, TC_QUERY_CAPS, &base);
893}
894EXPORT_SYMBOL(qdisc_offload_query_caps);
895
896static void qdisc_offload_graft_root(struct net_device *dev,
897 struct Qdisc *new, struct Qdisc *old,
898 struct netlink_ext_ack *extack)
899{
900 struct tc_root_qopt_offload graft_offload = {
901 .command = TC_ROOT_GRAFT,
902 .handle = new ? new->handle : 0,
903 .ingress = (new && new->flags & TCQ_F_INGRESS) ||
904 (old && old->flags & TCQ_F_INGRESS),
905 };
906
907 qdisc_offload_graft_helper(dev, NULL, new, old,
908 TC_SETUP_ROOT_QDISC, &graft_offload, extack);
909}
910
911static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
912 u32 portid, u32 seq, u16 flags, int event,
913 struct netlink_ext_ack *extack)
914{
915 struct gnet_stats_basic_sync __percpu *cpu_bstats = NULL;
916 struct gnet_stats_queue __percpu *cpu_qstats = NULL;
917 struct tcmsg *tcm;
918 struct nlmsghdr *nlh;
919 unsigned char *b = skb_tail_pointer(skb);
920 struct gnet_dump d;
921 struct qdisc_size_table *stab;
922 u32 block_index;
923 __u32 qlen;
924
925 cond_resched();
926 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
927 if (!nlh)
928 goto out_nlmsg_trim;
929 tcm = nlmsg_data(nlh);
930 tcm->tcm_family = AF_UNSPEC;
931 tcm->tcm__pad1 = 0;
932 tcm->tcm__pad2 = 0;
933 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
934 tcm->tcm_parent = clid;
935 tcm->tcm_handle = q->handle;
936 tcm->tcm_info = refcount_read(&q->refcnt);
937 if (nla_put_string(skb, TCA_KIND, q->ops->id))
938 goto nla_put_failure;
939 if (q->ops->ingress_block_get) {
940 block_index = q->ops->ingress_block_get(q);
941 if (block_index &&
942 nla_put_u32(skb, TCA_INGRESS_BLOCK, block_index))
943 goto nla_put_failure;
944 }
945 if (q->ops->egress_block_get) {
946 block_index = q->ops->egress_block_get(q);
947 if (block_index &&
948 nla_put_u32(skb, TCA_EGRESS_BLOCK, block_index))
949 goto nla_put_failure;
950 }
951 if (q->ops->dump && q->ops->dump(q, skb) < 0)
952 goto nla_put_failure;
953 if (nla_put_u8(skb, TCA_HW_OFFLOAD, !!(q->flags & TCQ_F_OFFLOADED)))
954 goto nla_put_failure;
955 qlen = qdisc_qlen_sum(q);
956
957 stab = rtnl_dereference(q->stab);
958 if (stab && qdisc_dump_stab(skb, stab) < 0)
959 goto nla_put_failure;
960
961 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
962 NULL, &d, TCA_PAD) < 0)
963 goto nla_put_failure;
964
965 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
966 goto nla_put_failure;
967
968 if (qdisc_is_percpu_stats(q)) {
969 cpu_bstats = q->cpu_bstats;
970 cpu_qstats = q->cpu_qstats;
971 }
972
973 if (gnet_stats_copy_basic(&d, cpu_bstats, &q->bstats, true) < 0 ||
974 gnet_stats_copy_rate_est(&d, &q->rate_est) < 0 ||
975 gnet_stats_copy_queue(&d, cpu_qstats, &q->qstats, qlen) < 0)
976 goto nla_put_failure;
977
978 if (gnet_stats_finish_copy(&d) < 0)
979 goto nla_put_failure;
980
981 if (extack && extack->_msg &&
982 nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg))
983 goto out_nlmsg_trim;
984
985 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
986
987 return skb->len;
988
989out_nlmsg_trim:
990nla_put_failure:
991 nlmsg_trim(skb, b);
992 return -1;
993}
994
995static bool tc_qdisc_dump_ignore(struct Qdisc *q, bool dump_invisible)
996{
997 if (q->flags & TCQ_F_BUILTIN)
998 return true;
999 if ((q->flags & TCQ_F_INVISIBLE) && !dump_invisible)
1000 return true;
1001
1002 return false;
1003}
1004
1005static int qdisc_get_notify(struct net *net, struct sk_buff *oskb,
1006 struct nlmsghdr *n, u32 clid, struct Qdisc *q,
1007 struct netlink_ext_ack *extack)
1008{
1009 struct sk_buff *skb;
1010 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1011
1012 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1013 if (!skb)
1014 return -ENOBUFS;
1015
1016 if (!tc_qdisc_dump_ignore(q, false)) {
1017 if (tc_fill_qdisc(skb, q, clid, portid, n->nlmsg_seq, 0,
1018 RTM_NEWQDISC, extack) < 0)
1019 goto err_out;
1020 }
1021
1022 if (skb->len)
1023 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1024 n->nlmsg_flags & NLM_F_ECHO);
1025
1026err_out:
1027 kfree_skb(skb);
1028 return -EINVAL;
1029}
1030
1031static int qdisc_notify(struct net *net, struct sk_buff *oskb,
1032 struct nlmsghdr *n, u32 clid,
1033 struct Qdisc *old, struct Qdisc *new,
1034 struct netlink_ext_ack *extack)
1035{
1036 struct sk_buff *skb;
1037 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1038
1039 if (!rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC))
1040 return 0;
1041
1042 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1043 if (!skb)
1044 return -ENOBUFS;
1045
1046 if (old && !tc_qdisc_dump_ignore(old, false)) {
1047 if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq,
1048 0, RTM_DELQDISC, extack) < 0)
1049 goto err_out;
1050 }
1051 if (new && !tc_qdisc_dump_ignore(new, false)) {
1052 if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq,
1053 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC, extack) < 0)
1054 goto err_out;
1055 }
1056
1057 if (skb->len)
1058 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1059 n->nlmsg_flags & NLM_F_ECHO);
1060
1061err_out:
1062 kfree_skb(skb);
1063 return -EINVAL;
1064}
1065
1066static void notify_and_destroy(struct net *net, struct sk_buff *skb,
1067 struct nlmsghdr *n, u32 clid,
1068 struct Qdisc *old, struct Qdisc *new,
1069 struct netlink_ext_ack *extack)
1070{
1071 if (new || old)
1072 qdisc_notify(net, skb, n, clid, old, new, extack);
1073
1074 if (old)
1075 qdisc_put(old);
1076}
1077
1078static void qdisc_clear_nolock(struct Qdisc *sch)
1079{
1080 sch->flags &= ~TCQ_F_NOLOCK;
1081 if (!(sch->flags & TCQ_F_CPUSTATS))
1082 return;
1083
1084 free_percpu(sch->cpu_bstats);
1085 free_percpu(sch->cpu_qstats);
1086 sch->cpu_bstats = NULL;
1087 sch->cpu_qstats = NULL;
1088 sch->flags &= ~TCQ_F_CPUSTATS;
1089}
1090
1091/* Graft qdisc "new" to class "classid" of qdisc "parent" or
1092 * to device "dev".
1093 *
1094 * When appropriate send a netlink notification using 'skb'
1095 * and "n".
1096 *
1097 * On success, destroy old qdisc.
1098 */
1099
1100static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
1101 struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
1102 struct Qdisc *new, struct Qdisc *old,
1103 struct netlink_ext_ack *extack)
1104{
1105 struct Qdisc *q = old;
1106 struct net *net = dev_net(dev);
1107
1108 if (parent == NULL) {
1109 unsigned int i, num_q, ingress;
1110 struct netdev_queue *dev_queue;
1111
1112 ingress = 0;
1113 num_q = dev->num_tx_queues;
1114 if ((q && q->flags & TCQ_F_INGRESS) ||
1115 (new && new->flags & TCQ_F_INGRESS)) {
1116 ingress = 1;
1117 dev_queue = dev_ingress_queue(dev);
1118 if (!dev_queue) {
1119 NL_SET_ERR_MSG(extack, "Device does not have an ingress queue");
1120 return -ENOENT;
1121 }
1122
1123 q = rtnl_dereference(dev_queue->qdisc_sleeping);
1124
1125 /* This is the counterpart of that qdisc_refcount_inc_nz() call in
1126 * __tcf_qdisc_find() for filter requests.
1127 */
1128 if (!qdisc_refcount_dec_if_one(q)) {
1129 NL_SET_ERR_MSG(extack,
1130 "Current ingress or clsact Qdisc has ongoing filter requests");
1131 return -EBUSY;
1132 }
1133 }
1134
1135 if (dev->flags & IFF_UP)
1136 dev_deactivate(dev);
1137
1138 qdisc_offload_graft_root(dev, new, old, extack);
1139
1140 if (new && new->ops->attach && !ingress)
1141 goto skip;
1142
1143 if (!ingress) {
1144 for (i = 0; i < num_q; i++) {
1145 dev_queue = netdev_get_tx_queue(dev, i);
1146 old = dev_graft_qdisc(dev_queue, new);
1147
1148 if (new && i > 0)
1149 qdisc_refcount_inc(new);
1150 qdisc_put(old);
1151 }
1152 } else {
1153 old = dev_graft_qdisc(dev_queue, NULL);
1154
1155 /* {ingress,clsact}_destroy() @old before grafting @new to avoid
1156 * unprotected concurrent accesses to net_device::miniq_{in,e}gress
1157 * pointer(s) in mini_qdisc_pair_swap().
1158 */
1159 qdisc_notify(net, skb, n, classid, old, new, extack);
1160 qdisc_destroy(old);
1161
1162 dev_graft_qdisc(dev_queue, new);
1163 }
1164
1165skip:
1166 if (!ingress) {
1167 old = rtnl_dereference(dev->qdisc);
1168 if (new && !new->ops->attach)
1169 qdisc_refcount_inc(new);
1170 rcu_assign_pointer(dev->qdisc, new ? : &noop_qdisc);
1171
1172 notify_and_destroy(net, skb, n, classid, old, new, extack);
1173
1174 if (new && new->ops->attach)
1175 new->ops->attach(new);
1176 }
1177
1178 if (dev->flags & IFF_UP)
1179 dev_activate(dev);
1180 } else {
1181 const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
1182 unsigned long cl;
1183 int err;
1184
1185 /* Only support running class lockless if parent is lockless */
1186 if (new && (new->flags & TCQ_F_NOLOCK) && !(parent->flags & TCQ_F_NOLOCK))
1187 qdisc_clear_nolock(new);
1188
1189 if (!cops || !cops->graft)
1190 return -EOPNOTSUPP;
1191
1192 cl = cops->find(parent, classid);
1193 if (!cl) {
1194 NL_SET_ERR_MSG(extack, "Specified class not found");
1195 return -ENOENT;
1196 }
1197
1198 if (new && new->ops == &noqueue_qdisc_ops) {
1199 NL_SET_ERR_MSG(extack, "Cannot assign noqueue to a class");
1200 return -EINVAL;
1201 }
1202
1203 if (new &&
1204 !(parent->flags & TCQ_F_MQROOT) &&
1205 rcu_access_pointer(new->stab)) {
1206 NL_SET_ERR_MSG(extack, "STAB not supported on a non root");
1207 return -EINVAL;
1208 }
1209 err = cops->graft(parent, cl, new, &old, extack);
1210 if (err)
1211 return err;
1212 notify_and_destroy(net, skb, n, classid, old, new, extack);
1213 }
1214 return 0;
1215}
1216
1217static int qdisc_block_indexes_set(struct Qdisc *sch, struct nlattr **tca,
1218 struct netlink_ext_ack *extack)
1219{
1220 u32 block_index;
1221
1222 if (tca[TCA_INGRESS_BLOCK]) {
1223 block_index = nla_get_u32(tca[TCA_INGRESS_BLOCK]);
1224
1225 if (!block_index) {
1226 NL_SET_ERR_MSG(extack, "Ingress block index cannot be 0");
1227 return -EINVAL;
1228 }
1229 if (!sch->ops->ingress_block_set) {
1230 NL_SET_ERR_MSG(extack, "Ingress block sharing is not supported");
1231 return -EOPNOTSUPP;
1232 }
1233 sch->ops->ingress_block_set(sch, block_index);
1234 }
1235 if (tca[TCA_EGRESS_BLOCK]) {
1236 block_index = nla_get_u32(tca[TCA_EGRESS_BLOCK]);
1237
1238 if (!block_index) {
1239 NL_SET_ERR_MSG(extack, "Egress block index cannot be 0");
1240 return -EINVAL;
1241 }
1242 if (!sch->ops->egress_block_set) {
1243 NL_SET_ERR_MSG(extack, "Egress block sharing is not supported");
1244 return -EOPNOTSUPP;
1245 }
1246 sch->ops->egress_block_set(sch, block_index);
1247 }
1248 return 0;
1249}
1250
1251/*
1252 Allocate and initialize new qdisc.
1253
1254 Parameters are passed via opt.
1255 */
1256
1257static struct Qdisc *qdisc_create(struct net_device *dev,
1258 struct netdev_queue *dev_queue,
1259 u32 parent, u32 handle,
1260 struct nlattr **tca, int *errp,
1261 struct netlink_ext_ack *extack)
1262{
1263 int err;
1264 struct nlattr *kind = tca[TCA_KIND];
1265 struct Qdisc *sch;
1266 struct Qdisc_ops *ops;
1267 struct qdisc_size_table *stab;
1268
1269 ops = qdisc_lookup_ops(kind);
1270#ifdef CONFIG_MODULES
1271 if (ops == NULL && kind != NULL) {
1272 char name[IFNAMSIZ];
1273 if (nla_strscpy(name, kind, IFNAMSIZ) >= 0) {
1274 /* We dropped the RTNL semaphore in order to
1275 * perform the module load. So, even if we
1276 * succeeded in loading the module we have to
1277 * tell the caller to replay the request. We
1278 * indicate this using -EAGAIN.
1279 * We replay the request because the device may
1280 * go away in the mean time.
1281 */
1282 rtnl_unlock();
1283 request_module(NET_SCH_ALIAS_PREFIX "%s", name);
1284 rtnl_lock();
1285 ops = qdisc_lookup_ops(kind);
1286 if (ops != NULL) {
1287 /* We will try again qdisc_lookup_ops,
1288 * so don't keep a reference.
1289 */
1290 module_put(ops->owner);
1291 err = -EAGAIN;
1292 goto err_out;
1293 }
1294 }
1295 }
1296#endif
1297
1298 err = -ENOENT;
1299 if (!ops) {
1300 NL_SET_ERR_MSG(extack, "Specified qdisc kind is unknown");
1301 goto err_out;
1302 }
1303
1304 sch = qdisc_alloc(dev_queue, ops, extack);
1305 if (IS_ERR(sch)) {
1306 err = PTR_ERR(sch);
1307 goto err_out2;
1308 }
1309
1310 sch->parent = parent;
1311
1312 if (handle == TC_H_INGRESS) {
1313 if (!(sch->flags & TCQ_F_INGRESS)) {
1314 NL_SET_ERR_MSG(extack,
1315 "Specified parent ID is reserved for ingress and clsact Qdiscs");
1316 err = -EINVAL;
1317 goto err_out3;
1318 }
1319 handle = TC_H_MAKE(TC_H_INGRESS, 0);
1320 } else {
1321 if (handle == 0) {
1322 handle = qdisc_alloc_handle(dev);
1323 if (handle == 0) {
1324 NL_SET_ERR_MSG(extack, "Maximum number of qdisc handles was exceeded");
1325 err = -ENOSPC;
1326 goto err_out3;
1327 }
1328 }
1329 if (!netif_is_multiqueue(dev))
1330 sch->flags |= TCQ_F_ONETXQUEUE;
1331 }
1332
1333 sch->handle = handle;
1334
1335 /* This exist to keep backward compatible with a userspace
1336 * loophole, what allowed userspace to get IFF_NO_QUEUE
1337 * facility on older kernels by setting tx_queue_len=0 (prior
1338 * to qdisc init), and then forgot to reinit tx_queue_len
1339 * before again attaching a qdisc.
1340 */
1341 if ((dev->priv_flags & IFF_NO_QUEUE) && (dev->tx_queue_len == 0)) {
1342 WRITE_ONCE(dev->tx_queue_len, DEFAULT_TX_QUEUE_LEN);
1343 netdev_info(dev, "Caught tx_queue_len zero misconfig\n");
1344 }
1345
1346 err = qdisc_block_indexes_set(sch, tca, extack);
1347 if (err)
1348 goto err_out3;
1349
1350 if (tca[TCA_STAB]) {
1351 stab = qdisc_get_stab(tca[TCA_STAB], extack);
1352 if (IS_ERR(stab)) {
1353 err = PTR_ERR(stab);
1354 goto err_out3;
1355 }
1356 rcu_assign_pointer(sch->stab, stab);
1357 }
1358
1359 if (ops->init) {
1360 err = ops->init(sch, tca[TCA_OPTIONS], extack);
1361 if (err != 0)
1362 goto err_out4;
1363 }
1364
1365 if (tca[TCA_RATE]) {
1366 err = -EOPNOTSUPP;
1367 if (sch->flags & TCQ_F_MQROOT) {
1368 NL_SET_ERR_MSG(extack, "Cannot attach rate estimator to a multi-queue root qdisc");
1369 goto err_out4;
1370 }
1371
1372 err = gen_new_estimator(&sch->bstats,
1373 sch->cpu_bstats,
1374 &sch->rate_est,
1375 NULL,
1376 true,
1377 tca[TCA_RATE]);
1378 if (err) {
1379 NL_SET_ERR_MSG(extack, "Failed to generate new estimator");
1380 goto err_out4;
1381 }
1382 }
1383
1384 qdisc_hash_add(sch, false);
1385 trace_qdisc_create(ops, dev, parent);
1386
1387 return sch;
1388
1389err_out4:
1390 /* Even if ops->init() failed, we call ops->destroy()
1391 * like qdisc_create_dflt().
1392 */
1393 if (ops->destroy)
1394 ops->destroy(sch);
1395 qdisc_put_stab(rtnl_dereference(sch->stab));
1396err_out3:
1397 lockdep_unregister_key(&sch->root_lock_key);
1398 netdev_put(dev, &sch->dev_tracker);
1399 qdisc_free(sch);
1400err_out2:
1401 module_put(ops->owner);
1402err_out:
1403 *errp = err;
1404 return NULL;
1405}
1406
1407static int qdisc_change(struct Qdisc *sch, struct nlattr **tca,
1408 struct netlink_ext_ack *extack)
1409{
1410 struct qdisc_size_table *ostab, *stab = NULL;
1411 int err = 0;
1412
1413 if (tca[TCA_OPTIONS]) {
1414 if (!sch->ops->change) {
1415 NL_SET_ERR_MSG(extack, "Change operation not supported by specified qdisc");
1416 return -EINVAL;
1417 }
1418 if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) {
1419 NL_SET_ERR_MSG(extack, "Change of blocks is not supported");
1420 return -EOPNOTSUPP;
1421 }
1422 err = sch->ops->change(sch, tca[TCA_OPTIONS], extack);
1423 if (err)
1424 return err;
1425 }
1426
1427 if (tca[TCA_STAB]) {
1428 stab = qdisc_get_stab(tca[TCA_STAB], extack);
1429 if (IS_ERR(stab))
1430 return PTR_ERR(stab);
1431 }
1432
1433 ostab = rtnl_dereference(sch->stab);
1434 rcu_assign_pointer(sch->stab, stab);
1435 qdisc_put_stab(ostab);
1436
1437 if (tca[TCA_RATE]) {
1438 /* NB: ignores errors from replace_estimator
1439 because change can't be undone. */
1440 if (sch->flags & TCQ_F_MQROOT)
1441 goto out;
1442 gen_replace_estimator(&sch->bstats,
1443 sch->cpu_bstats,
1444 &sch->rate_est,
1445 NULL,
1446 true,
1447 tca[TCA_RATE]);
1448 }
1449out:
1450 return 0;
1451}
1452
1453struct check_loop_arg {
1454 struct qdisc_walker w;
1455 struct Qdisc *p;
1456 int depth;
1457};
1458
1459static int check_loop_fn(struct Qdisc *q, unsigned long cl,
1460 struct qdisc_walker *w);
1461
1462static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
1463{
1464 struct check_loop_arg arg;
1465
1466 if (q->ops->cl_ops == NULL)
1467 return 0;
1468
1469 arg.w.stop = arg.w.skip = arg.w.count = 0;
1470 arg.w.fn = check_loop_fn;
1471 arg.depth = depth;
1472 arg.p = p;
1473 q->ops->cl_ops->walk(q, &arg.w);
1474 return arg.w.stop ? -ELOOP : 0;
1475}
1476
1477static int
1478check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
1479{
1480 struct Qdisc *leaf;
1481 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1482 struct check_loop_arg *arg = (struct check_loop_arg *)w;
1483
1484 leaf = cops->leaf(q, cl);
1485 if (leaf) {
1486 if (leaf == arg->p || arg->depth > 7)
1487 return -ELOOP;
1488 return check_loop(leaf, arg->p, arg->depth + 1);
1489 }
1490 return 0;
1491}
1492
1493const struct nla_policy rtm_tca_policy[TCA_MAX + 1] = {
1494 [TCA_KIND] = { .type = NLA_STRING },
1495 [TCA_RATE] = { .type = NLA_BINARY,
1496 .len = sizeof(struct tc_estimator) },
1497 [TCA_STAB] = { .type = NLA_NESTED },
1498 [TCA_DUMP_INVISIBLE] = { .type = NLA_FLAG },
1499 [TCA_CHAIN] = { .type = NLA_U32 },
1500 [TCA_INGRESS_BLOCK] = { .type = NLA_U32 },
1501 [TCA_EGRESS_BLOCK] = { .type = NLA_U32 },
1502};
1503
1504/*
1505 * Delete/get qdisc.
1506 */
1507
1508static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
1509 struct netlink_ext_ack *extack)
1510{
1511 struct net *net = sock_net(skb->sk);
1512 struct tcmsg *tcm = nlmsg_data(n);
1513 struct nlattr *tca[TCA_MAX + 1];
1514 struct net_device *dev;
1515 u32 clid;
1516 struct Qdisc *q = NULL;
1517 struct Qdisc *p = NULL;
1518 int err;
1519
1520 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
1521 rtm_tca_policy, extack);
1522 if (err < 0)
1523 return err;
1524
1525 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1526 if (!dev)
1527 return -ENODEV;
1528
1529 clid = tcm->tcm_parent;
1530 if (clid) {
1531 if (clid != TC_H_ROOT) {
1532 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
1533 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1534 if (!p) {
1535 NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified classid");
1536 return -ENOENT;
1537 }
1538 q = qdisc_leaf(p, clid);
1539 } else if (dev_ingress_queue(dev)) {
1540 q = rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping);
1541 }
1542 } else {
1543 q = rtnl_dereference(dev->qdisc);
1544 }
1545 if (!q) {
1546 NL_SET_ERR_MSG(extack, "Cannot find specified qdisc on specified device");
1547 return -ENOENT;
1548 }
1549
1550 if (tcm->tcm_handle && q->handle != tcm->tcm_handle) {
1551 NL_SET_ERR_MSG(extack, "Invalid handle");
1552 return -EINVAL;
1553 }
1554 } else {
1555 q = qdisc_lookup(dev, tcm->tcm_handle);
1556 if (!q) {
1557 NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified handle");
1558 return -ENOENT;
1559 }
1560 }
1561
1562 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1563 NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1564 return -EINVAL;
1565 }
1566
1567 if (n->nlmsg_type == RTM_DELQDISC) {
1568 if (!clid) {
1569 NL_SET_ERR_MSG(extack, "Classid cannot be zero");
1570 return -EINVAL;
1571 }
1572 if (q->handle == 0) {
1573 NL_SET_ERR_MSG(extack, "Cannot delete qdisc with handle of zero");
1574 return -ENOENT;
1575 }
1576 err = qdisc_graft(dev, p, skb, n, clid, NULL, q, extack);
1577 if (err != 0)
1578 return err;
1579 } else {
1580 qdisc_get_notify(net, skb, n, clid, q, NULL);
1581 }
1582 return 0;
1583}
1584
1585static bool req_create_or_replace(struct nlmsghdr *n)
1586{
1587 return (n->nlmsg_flags & NLM_F_CREATE &&
1588 n->nlmsg_flags & NLM_F_REPLACE);
1589}
1590
1591static bool req_create_exclusive(struct nlmsghdr *n)
1592{
1593 return (n->nlmsg_flags & NLM_F_CREATE &&
1594 n->nlmsg_flags & NLM_F_EXCL);
1595}
1596
1597static bool req_change(struct nlmsghdr *n)
1598{
1599 return (!(n->nlmsg_flags & NLM_F_CREATE) &&
1600 !(n->nlmsg_flags & NLM_F_REPLACE) &&
1601 !(n->nlmsg_flags & NLM_F_EXCL));
1602}
1603
1604/*
1605 * Create/change qdisc.
1606 */
1607static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
1608 struct netlink_ext_ack *extack)
1609{
1610 struct net *net = sock_net(skb->sk);
1611 struct tcmsg *tcm;
1612 struct nlattr *tca[TCA_MAX + 1];
1613 struct net_device *dev;
1614 u32 clid;
1615 struct Qdisc *q, *p;
1616 int err;
1617
1618replay:
1619 /* Reinit, just in case something touches this. */
1620 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
1621 rtm_tca_policy, extack);
1622 if (err < 0)
1623 return err;
1624
1625 tcm = nlmsg_data(n);
1626 clid = tcm->tcm_parent;
1627 q = p = NULL;
1628
1629 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1630 if (!dev)
1631 return -ENODEV;
1632
1633
1634 if (clid) {
1635 if (clid != TC_H_ROOT) {
1636 if (clid != TC_H_INGRESS) {
1637 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1638 if (!p) {
1639 NL_SET_ERR_MSG(extack, "Failed to find specified qdisc");
1640 return -ENOENT;
1641 }
1642 q = qdisc_leaf(p, clid);
1643 } else if (dev_ingress_queue_create(dev)) {
1644 q = rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping);
1645 }
1646 } else {
1647 q = rtnl_dereference(dev->qdisc);
1648 }
1649
1650 /* It may be default qdisc, ignore it */
1651 if (q && q->handle == 0)
1652 q = NULL;
1653
1654 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1655 if (tcm->tcm_handle) {
1656 if (q && !(n->nlmsg_flags & NLM_F_REPLACE)) {
1657 NL_SET_ERR_MSG(extack, "NLM_F_REPLACE needed to override");
1658 return -EEXIST;
1659 }
1660 if (TC_H_MIN(tcm->tcm_handle)) {
1661 NL_SET_ERR_MSG(extack, "Invalid minor handle");
1662 return -EINVAL;
1663 }
1664 q = qdisc_lookup(dev, tcm->tcm_handle);
1665 if (!q)
1666 goto create_n_graft;
1667 if (q->parent != tcm->tcm_parent) {
1668 NL_SET_ERR_MSG(extack, "Cannot move an existing qdisc to a different parent");
1669 return -EINVAL;
1670 }
1671 if (n->nlmsg_flags & NLM_F_EXCL) {
1672 NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot override");
1673 return -EEXIST;
1674 }
1675 if (tca[TCA_KIND] &&
1676 nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1677 NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1678 return -EINVAL;
1679 }
1680 if (q->flags & TCQ_F_INGRESS) {
1681 NL_SET_ERR_MSG(extack,
1682 "Cannot regraft ingress or clsact Qdiscs");
1683 return -EINVAL;
1684 }
1685 if (q == p ||
1686 (p && check_loop(q, p, 0))) {
1687 NL_SET_ERR_MSG(extack, "Qdisc parent/child loop detected");
1688 return -ELOOP;
1689 }
1690 if (clid == TC_H_INGRESS) {
1691 NL_SET_ERR_MSG(extack, "Ingress cannot graft directly");
1692 return -EINVAL;
1693 }
1694 qdisc_refcount_inc(q);
1695 goto graft;
1696 } else {
1697 if (!q)
1698 goto create_n_graft;
1699
1700 /* This magic test requires explanation.
1701 *
1702 * We know, that some child q is already
1703 * attached to this parent and have choice:
1704 * 1) change it or 2) create/graft new one.
1705 * If the requested qdisc kind is different
1706 * than the existing one, then we choose graft.
1707 * If they are the same then this is "change"
1708 * operation - just let it fallthrough..
1709 *
1710 * 1. We are allowed to create/graft only
1711 * if the request is explicitly stating
1712 * "please create if it doesn't exist".
1713 *
1714 * 2. If the request is to exclusive create
1715 * then the qdisc tcm_handle is not expected
1716 * to exist, so that we choose create/graft too.
1717 *
1718 * 3. The last case is when no flags are set.
1719 * This will happen when for example tc
1720 * utility issues a "change" command.
1721 * Alas, it is sort of hole in API, we
1722 * cannot decide what to do unambiguously.
1723 * For now we select create/graft.
1724 */
1725 if (tca[TCA_KIND] &&
1726 nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1727 if (req_create_or_replace(n) ||
1728 req_create_exclusive(n))
1729 goto create_n_graft;
1730 else if (req_change(n))
1731 goto create_n_graft2;
1732 }
1733 }
1734 }
1735 } else {
1736 if (!tcm->tcm_handle) {
1737 NL_SET_ERR_MSG(extack, "Handle cannot be zero");
1738 return -EINVAL;
1739 }
1740 q = qdisc_lookup(dev, tcm->tcm_handle);
1741 }
1742
1743 /* Change qdisc parameters */
1744 if (!q) {
1745 NL_SET_ERR_MSG(extack, "Specified qdisc not found");
1746 return -ENOENT;
1747 }
1748 if (n->nlmsg_flags & NLM_F_EXCL) {
1749 NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot modify");
1750 return -EEXIST;
1751 }
1752 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1753 NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1754 return -EINVAL;
1755 }
1756 err = qdisc_change(q, tca, extack);
1757 if (err == 0)
1758 qdisc_notify(net, skb, n, clid, NULL, q, extack);
1759 return err;
1760
1761create_n_graft:
1762 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
1763 NL_SET_ERR_MSG(extack, "Qdisc not found. To create specify NLM_F_CREATE flag");
1764 return -ENOENT;
1765 }
1766create_n_graft2:
1767 if (clid == TC_H_INGRESS) {
1768 if (dev_ingress_queue(dev)) {
1769 q = qdisc_create(dev, dev_ingress_queue(dev),
1770 tcm->tcm_parent, tcm->tcm_parent,
1771 tca, &err, extack);
1772 } else {
1773 NL_SET_ERR_MSG(extack, "Cannot find ingress queue for specified device");
1774 err = -ENOENT;
1775 }
1776 } else {
1777 struct netdev_queue *dev_queue;
1778
1779 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1780 dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1781 else if (p)
1782 dev_queue = p->dev_queue;
1783 else
1784 dev_queue = netdev_get_tx_queue(dev, 0);
1785
1786 q = qdisc_create(dev, dev_queue,
1787 tcm->tcm_parent, tcm->tcm_handle,
1788 tca, &err, extack);
1789 }
1790 if (q == NULL) {
1791 if (err == -EAGAIN)
1792 goto replay;
1793 return err;
1794 }
1795
1796graft:
1797 err = qdisc_graft(dev, p, skb, n, clid, q, NULL, extack);
1798 if (err) {
1799 if (q)
1800 qdisc_put(q);
1801 return err;
1802 }
1803
1804 return 0;
1805}
1806
1807static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1808 struct netlink_callback *cb,
1809 int *q_idx_p, int s_q_idx, bool recur,
1810 bool dump_invisible)
1811{
1812 int ret = 0, q_idx = *q_idx_p;
1813 struct Qdisc *q;
1814 int b;
1815
1816 if (!root)
1817 return 0;
1818
1819 q = root;
1820 if (q_idx < s_q_idx) {
1821 q_idx++;
1822 } else {
1823 if (!tc_qdisc_dump_ignore(q, dump_invisible) &&
1824 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1825 cb->nlh->nlmsg_seq, NLM_F_MULTI,
1826 RTM_NEWQDISC, NULL) <= 0)
1827 goto done;
1828 q_idx++;
1829 }
1830
1831 /* If dumping singletons, there is no qdisc_dev(root) and the singleton
1832 * itself has already been dumped.
1833 *
1834 * If we've already dumped the top-level (ingress) qdisc above and the global
1835 * qdisc hashtable, we don't want to hit it again
1836 */
1837 if (!qdisc_dev(root) || !recur)
1838 goto out;
1839
1840 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
1841 if (q_idx < s_q_idx) {
1842 q_idx++;
1843 continue;
1844 }
1845 if (!tc_qdisc_dump_ignore(q, dump_invisible) &&
1846 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1847 cb->nlh->nlmsg_seq, NLM_F_MULTI,
1848 RTM_NEWQDISC, NULL) <= 0)
1849 goto done;
1850 q_idx++;
1851 }
1852
1853out:
1854 *q_idx_p = q_idx;
1855 return ret;
1856done:
1857 ret = -1;
1858 goto out;
1859}
1860
1861static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1862{
1863 struct net *net = sock_net(skb->sk);
1864 int idx, q_idx;
1865 int s_idx, s_q_idx;
1866 struct net_device *dev;
1867 const struct nlmsghdr *nlh = cb->nlh;
1868 struct nlattr *tca[TCA_MAX + 1];
1869 int err;
1870
1871 s_idx = cb->args[0];
1872 s_q_idx = q_idx = cb->args[1];
1873
1874 idx = 0;
1875 ASSERT_RTNL();
1876
1877 err = nlmsg_parse_deprecated(nlh, sizeof(struct tcmsg), tca, TCA_MAX,
1878 rtm_tca_policy, cb->extack);
1879 if (err < 0)
1880 return err;
1881
1882 for_each_netdev(net, dev) {
1883 struct netdev_queue *dev_queue;
1884
1885 if (idx < s_idx)
1886 goto cont;
1887 if (idx > s_idx)
1888 s_q_idx = 0;
1889 q_idx = 0;
1890
1891 if (tc_dump_qdisc_root(rtnl_dereference(dev->qdisc),
1892 skb, cb, &q_idx, s_q_idx,
1893 true, tca[TCA_DUMP_INVISIBLE]) < 0)
1894 goto done;
1895
1896 dev_queue = dev_ingress_queue(dev);
1897 if (dev_queue &&
1898 tc_dump_qdisc_root(rtnl_dereference(dev_queue->qdisc_sleeping),
1899 skb, cb, &q_idx, s_q_idx, false,
1900 tca[TCA_DUMP_INVISIBLE]) < 0)
1901 goto done;
1902
1903cont:
1904 idx++;
1905 }
1906
1907done:
1908 cb->args[0] = idx;
1909 cb->args[1] = q_idx;
1910
1911 return skb->len;
1912}
1913
1914
1915
1916/************************************************
1917 * Traffic classes manipulation. *
1918 ************************************************/
1919
1920static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1921 unsigned long cl, u32 portid, u32 seq, u16 flags,
1922 int event, struct netlink_ext_ack *extack)
1923{
1924 struct tcmsg *tcm;
1925 struct nlmsghdr *nlh;
1926 unsigned char *b = skb_tail_pointer(skb);
1927 struct gnet_dump d;
1928 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1929
1930 cond_resched();
1931 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1932 if (!nlh)
1933 goto out_nlmsg_trim;
1934 tcm = nlmsg_data(nlh);
1935 tcm->tcm_family = AF_UNSPEC;
1936 tcm->tcm__pad1 = 0;
1937 tcm->tcm__pad2 = 0;
1938 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1939 tcm->tcm_parent = q->handle;
1940 tcm->tcm_handle = q->handle;
1941 tcm->tcm_info = 0;
1942 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1943 goto nla_put_failure;
1944 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1945 goto nla_put_failure;
1946
1947 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1948 NULL, &d, TCA_PAD) < 0)
1949 goto nla_put_failure;
1950
1951 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1952 goto nla_put_failure;
1953
1954 if (gnet_stats_finish_copy(&d) < 0)
1955 goto nla_put_failure;
1956
1957 if (extack && extack->_msg &&
1958 nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg))
1959 goto out_nlmsg_trim;
1960
1961 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1962
1963 return skb->len;
1964
1965out_nlmsg_trim:
1966nla_put_failure:
1967 nlmsg_trim(skb, b);
1968 return -1;
1969}
1970
1971static int tclass_notify(struct net *net, struct sk_buff *oskb,
1972 struct nlmsghdr *n, struct Qdisc *q,
1973 unsigned long cl, int event, struct netlink_ext_ack *extack)
1974{
1975 struct sk_buff *skb;
1976 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1977
1978 if (!rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC))
1979 return 0;
1980
1981 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1982 if (!skb)
1983 return -ENOBUFS;
1984
1985 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event, extack) < 0) {
1986 kfree_skb(skb);
1987 return -EINVAL;
1988 }
1989
1990 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1991 n->nlmsg_flags & NLM_F_ECHO);
1992}
1993
1994static int tclass_get_notify(struct net *net, struct sk_buff *oskb,
1995 struct nlmsghdr *n, struct Qdisc *q,
1996 unsigned long cl, struct netlink_ext_ack *extack)
1997{
1998 struct sk_buff *skb;
1999 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2000
2001 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2002 if (!skb)
2003 return -ENOBUFS;
2004
2005 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, RTM_NEWTCLASS,
2006 extack) < 0) {
2007 kfree_skb(skb);
2008 return -EINVAL;
2009 }
2010
2011 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
2012 n->nlmsg_flags & NLM_F_ECHO);
2013}
2014
2015static int tclass_del_notify(struct net *net,
2016 const struct Qdisc_class_ops *cops,
2017 struct sk_buff *oskb, struct nlmsghdr *n,
2018 struct Qdisc *q, unsigned long cl,
2019 struct netlink_ext_ack *extack)
2020{
2021 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2022 struct sk_buff *skb;
2023 int err = 0;
2024
2025 if (!cops->delete)
2026 return -EOPNOTSUPP;
2027
2028 if (rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC)) {
2029 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2030 if (!skb)
2031 return -ENOBUFS;
2032
2033 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0,
2034 RTM_DELTCLASS, extack) < 0) {
2035 kfree_skb(skb);
2036 return -EINVAL;
2037 }
2038 } else {
2039 skb = NULL;
2040 }
2041
2042 err = cops->delete(q, cl, extack);
2043 if (err) {
2044 kfree_skb(skb);
2045 return err;
2046 }
2047
2048 err = rtnetlink_maybe_send(skb, net, portid, RTNLGRP_TC,
2049 n->nlmsg_flags & NLM_F_ECHO);
2050 return err;
2051}
2052
2053#ifdef CONFIG_NET_CLS
2054
2055struct tcf_bind_args {
2056 struct tcf_walker w;
2057 unsigned long base;
2058 unsigned long cl;
2059 u32 classid;
2060};
2061
2062static int tcf_node_bind(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
2063{
2064 struct tcf_bind_args *a = (void *)arg;
2065
2066 if (n && tp->ops->bind_class) {
2067 struct Qdisc *q = tcf_block_q(tp->chain->block);
2068
2069 sch_tree_lock(q);
2070 tp->ops->bind_class(n, a->classid, a->cl, q, a->base);
2071 sch_tree_unlock(q);
2072 }
2073 return 0;
2074}
2075
2076struct tc_bind_class_args {
2077 struct qdisc_walker w;
2078 unsigned long new_cl;
2079 u32 portid;
2080 u32 clid;
2081};
2082
2083static int tc_bind_class_walker(struct Qdisc *q, unsigned long cl,
2084 struct qdisc_walker *w)
2085{
2086 struct tc_bind_class_args *a = (struct tc_bind_class_args *)w;
2087 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
2088 struct tcf_block *block;
2089 struct tcf_chain *chain;
2090
2091 block = cops->tcf_block(q, cl, NULL);
2092 if (!block)
2093 return 0;
2094 for (chain = tcf_get_next_chain(block, NULL);
2095 chain;
2096 chain = tcf_get_next_chain(block, chain)) {
2097 struct tcf_proto *tp;
2098
2099 for (tp = tcf_get_next_proto(chain, NULL);
2100 tp; tp = tcf_get_next_proto(chain, tp)) {
2101 struct tcf_bind_args arg = {};
2102
2103 arg.w.fn = tcf_node_bind;
2104 arg.classid = a->clid;
2105 arg.base = cl;
2106 arg.cl = a->new_cl;
2107 tp->ops->walk(tp, &arg.w, true);
2108 }
2109 }
2110
2111 return 0;
2112}
2113
2114static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
2115 unsigned long new_cl)
2116{
2117 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
2118 struct tc_bind_class_args args = {};
2119
2120 if (!cops->tcf_block)
2121 return;
2122 args.portid = portid;
2123 args.clid = clid;
2124 args.new_cl = new_cl;
2125 args.w.fn = tc_bind_class_walker;
2126 q->ops->cl_ops->walk(q, &args.w);
2127}
2128
2129#else
2130
2131static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
2132 unsigned long new_cl)
2133{
2134}
2135
2136#endif
2137
2138static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n,
2139 struct netlink_ext_ack *extack)
2140{
2141 struct net *net = sock_net(skb->sk);
2142 struct tcmsg *tcm = nlmsg_data(n);
2143 struct nlattr *tca[TCA_MAX + 1];
2144 struct net_device *dev;
2145 struct Qdisc *q = NULL;
2146 const struct Qdisc_class_ops *cops;
2147 unsigned long cl = 0;
2148 unsigned long new_cl;
2149 u32 portid;
2150 u32 clid;
2151 u32 qid;
2152 int err;
2153
2154 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
2155 rtm_tca_policy, extack);
2156 if (err < 0)
2157 return err;
2158
2159 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
2160 if (!dev)
2161 return -ENODEV;
2162
2163 /*
2164 parent == TC_H_UNSPEC - unspecified parent.
2165 parent == TC_H_ROOT - class is root, which has no parent.
2166 parent == X:0 - parent is root class.
2167 parent == X:Y - parent is a node in hierarchy.
2168 parent == 0:Y - parent is X:Y, where X:0 is qdisc.
2169
2170 handle == 0:0 - generate handle from kernel pool.
2171 handle == 0:Y - class is X:Y, where X:0 is qdisc.
2172 handle == X:Y - clear.
2173 handle == X:0 - root class.
2174 */
2175
2176 /* Step 1. Determine qdisc handle X:0 */
2177
2178 portid = tcm->tcm_parent;
2179 clid = tcm->tcm_handle;
2180 qid = TC_H_MAJ(clid);
2181
2182 if (portid != TC_H_ROOT) {
2183 u32 qid1 = TC_H_MAJ(portid);
2184
2185 if (qid && qid1) {
2186 /* If both majors are known, they must be identical. */
2187 if (qid != qid1)
2188 return -EINVAL;
2189 } else if (qid1) {
2190 qid = qid1;
2191 } else if (qid == 0)
2192 qid = rtnl_dereference(dev->qdisc)->handle;
2193
2194 /* Now qid is genuine qdisc handle consistent
2195 * both with parent and child.
2196 *
2197 * TC_H_MAJ(portid) still may be unspecified, complete it now.
2198 */
2199 if (portid)
2200 portid = TC_H_MAKE(qid, portid);
2201 } else {
2202 if (qid == 0)
2203 qid = rtnl_dereference(dev->qdisc)->handle;
2204 }
2205
2206 /* OK. Locate qdisc */
2207 q = qdisc_lookup(dev, qid);
2208 if (!q)
2209 return -ENOENT;
2210
2211 /* An check that it supports classes */
2212 cops = q->ops->cl_ops;
2213 if (cops == NULL)
2214 return -EINVAL;
2215
2216 /* Now try to get class */
2217 if (clid == 0) {
2218 if (portid == TC_H_ROOT)
2219 clid = qid;
2220 } else
2221 clid = TC_H_MAKE(qid, clid);
2222
2223 if (clid)
2224 cl = cops->find(q, clid);
2225
2226 if (cl == 0) {
2227 err = -ENOENT;
2228 if (n->nlmsg_type != RTM_NEWTCLASS ||
2229 !(n->nlmsg_flags & NLM_F_CREATE))
2230 goto out;
2231 } else {
2232 switch (n->nlmsg_type) {
2233 case RTM_NEWTCLASS:
2234 err = -EEXIST;
2235 if (n->nlmsg_flags & NLM_F_EXCL)
2236 goto out;
2237 break;
2238 case RTM_DELTCLASS:
2239 err = tclass_del_notify(net, cops, skb, n, q, cl, extack);
2240 /* Unbind the class with flilters with 0 */
2241 tc_bind_tclass(q, portid, clid, 0);
2242 goto out;
2243 case RTM_GETTCLASS:
2244 err = tclass_get_notify(net, skb, n, q, cl, extack);
2245 goto out;
2246 default:
2247 err = -EINVAL;
2248 goto out;
2249 }
2250 }
2251
2252 if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) {
2253 NL_SET_ERR_MSG(extack, "Shared blocks are not supported for classes");
2254 return -EOPNOTSUPP;
2255 }
2256
2257 new_cl = cl;
2258 err = -EOPNOTSUPP;
2259 if (cops->change)
2260 err = cops->change(q, clid, portid, tca, &new_cl, extack);
2261 if (err == 0) {
2262 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS, extack);
2263 /* We just create a new class, need to do reverse binding. */
2264 if (cl != new_cl)
2265 tc_bind_tclass(q, portid, clid, new_cl);
2266 }
2267out:
2268 return err;
2269}
2270
2271struct qdisc_dump_args {
2272 struct qdisc_walker w;
2273 struct sk_buff *skb;
2274 struct netlink_callback *cb;
2275};
2276
2277static int qdisc_class_dump(struct Qdisc *q, unsigned long cl,
2278 struct qdisc_walker *arg)
2279{
2280 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
2281
2282 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid,
2283 a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
2284 RTM_NEWTCLASS, NULL);
2285}
2286
2287static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
2288 struct tcmsg *tcm, struct netlink_callback *cb,
2289 int *t_p, int s_t)
2290{
2291 struct qdisc_dump_args arg;
2292
2293 if (tc_qdisc_dump_ignore(q, false) ||
2294 *t_p < s_t || !q->ops->cl_ops ||
2295 (tcm->tcm_parent &&
2296 TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
2297 (*t_p)++;
2298 return 0;
2299 }
2300 if (*t_p > s_t)
2301 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
2302 arg.w.fn = qdisc_class_dump;
2303 arg.skb = skb;
2304 arg.cb = cb;
2305 arg.w.stop = 0;
2306 arg.w.skip = cb->args[1];
2307 arg.w.count = 0;
2308 q->ops->cl_ops->walk(q, &arg.w);
2309 cb->args[1] = arg.w.count;
2310 if (arg.w.stop)
2311 return -1;
2312 (*t_p)++;
2313 return 0;
2314}
2315
2316static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
2317 struct tcmsg *tcm, struct netlink_callback *cb,
2318 int *t_p, int s_t, bool recur)
2319{
2320 struct Qdisc *q;
2321 int b;
2322
2323 if (!root)
2324 return 0;
2325
2326 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
2327 return -1;
2328
2329 if (!qdisc_dev(root) || !recur)
2330 return 0;
2331
2332 if (tcm->tcm_parent) {
2333 q = qdisc_match_from_root(root, TC_H_MAJ(tcm->tcm_parent));
2334 if (q && q != root &&
2335 tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
2336 return -1;
2337 return 0;
2338 }
2339 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
2340 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
2341 return -1;
2342 }
2343
2344 return 0;
2345}
2346
2347static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
2348{
2349 struct tcmsg *tcm = nlmsg_data(cb->nlh);
2350 struct net *net = sock_net(skb->sk);
2351 struct netdev_queue *dev_queue;
2352 struct net_device *dev;
2353 int t, s_t;
2354
2355 if (nlmsg_len(cb->nlh) < sizeof(*tcm))
2356 return 0;
2357 dev = dev_get_by_index(net, tcm->tcm_ifindex);
2358 if (!dev)
2359 return 0;
2360
2361 s_t = cb->args[0];
2362 t = 0;
2363
2364 if (tc_dump_tclass_root(rtnl_dereference(dev->qdisc),
2365 skb, tcm, cb, &t, s_t, true) < 0)
2366 goto done;
2367
2368 dev_queue = dev_ingress_queue(dev);
2369 if (dev_queue &&
2370 tc_dump_tclass_root(rtnl_dereference(dev_queue->qdisc_sleeping),
2371 skb, tcm, cb, &t, s_t, false) < 0)
2372 goto done;
2373
2374done:
2375 cb->args[0] = t;
2376
2377 dev_put(dev);
2378 return skb->len;
2379}
2380
2381#ifdef CONFIG_PROC_FS
2382static int psched_show(struct seq_file *seq, void *v)
2383{
2384 seq_printf(seq, "%08x %08x %08x %08x\n",
2385 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
2386 1000000,
2387 (u32)NSEC_PER_SEC / hrtimer_resolution);
2388
2389 return 0;
2390}
2391
2392static int __net_init psched_net_init(struct net *net)
2393{
2394 struct proc_dir_entry *e;
2395
2396 e = proc_create_single("psched", 0, net->proc_net, psched_show);
2397 if (e == NULL)
2398 return -ENOMEM;
2399
2400 return 0;
2401}
2402
2403static void __net_exit psched_net_exit(struct net *net)
2404{
2405 remove_proc_entry("psched", net->proc_net);
2406}
2407#else
2408static int __net_init psched_net_init(struct net *net)
2409{
2410 return 0;
2411}
2412
2413static void __net_exit psched_net_exit(struct net *net)
2414{
2415}
2416#endif
2417
2418static struct pernet_operations psched_net_ops = {
2419 .init = psched_net_init,
2420 .exit = psched_net_exit,
2421};
2422
2423#if IS_ENABLED(CONFIG_MITIGATION_RETPOLINE)
2424DEFINE_STATIC_KEY_FALSE(tc_skip_wrapper);
2425#endif
2426
2427static const struct rtnl_msg_handler psched_rtnl_msg_handlers[] __initconst = {
2428 {.msgtype = RTM_NEWQDISC, .doit = tc_modify_qdisc},
2429 {.msgtype = RTM_DELQDISC, .doit = tc_get_qdisc},
2430 {.msgtype = RTM_GETQDISC, .doit = tc_get_qdisc,
2431 .dumpit = tc_dump_qdisc},
2432 {.msgtype = RTM_NEWTCLASS, .doit = tc_ctl_tclass},
2433 {.msgtype = RTM_DELTCLASS, .doit = tc_ctl_tclass},
2434 {.msgtype = RTM_GETTCLASS, .doit = tc_ctl_tclass,
2435 .dumpit = tc_dump_tclass},
2436};
2437
2438static int __init pktsched_init(void)
2439{
2440 int err;
2441
2442 err = register_pernet_subsys(&psched_net_ops);
2443 if (err) {
2444 pr_err("pktsched_init: "
2445 "cannot initialize per netns operations\n");
2446 return err;
2447 }
2448
2449 register_qdisc(&pfifo_fast_ops);
2450 register_qdisc(&pfifo_qdisc_ops);
2451 register_qdisc(&bfifo_qdisc_ops);
2452 register_qdisc(&pfifo_head_drop_qdisc_ops);
2453 register_qdisc(&mq_qdisc_ops);
2454 register_qdisc(&noqueue_qdisc_ops);
2455
2456 rtnl_register_many(psched_rtnl_msg_handlers);
2457
2458 tc_wrapper_init();
2459
2460 return 0;
2461}
2462
2463subsys_initcall(pktsched_init);
1/*
2 * net/sched/sch_api.c Packet scheduler API.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 *
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 *
11 * Fixes:
12 *
13 * Rani Assaf <rani@magic.metawire.com> :980802: JIFFIES and CPU clock sources are repaired.
14 * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
15 * Jamal Hadi Salim <hadi@nortelnetworks.com>: 990601: ingress support
16 */
17
18#include <linux/module.h>
19#include <linux/types.h>
20#include <linux/kernel.h>
21#include <linux/string.h>
22#include <linux/errno.h>
23#include <linux/skbuff.h>
24#include <linux/init.h>
25#include <linux/proc_fs.h>
26#include <linux/seq_file.h>
27#include <linux/kmod.h>
28#include <linux/list.h>
29#include <linux/hrtimer.h>
30#include <linux/lockdep.h>
31#include <linux/slab.h>
32#include <linux/hashtable.h>
33
34#include <net/net_namespace.h>
35#include <net/sock.h>
36#include <net/netlink.h>
37#include <net/pkt_sched.h>
38#include <net/pkt_cls.h>
39
40/*
41
42 Short review.
43 -------------
44
45 This file consists of two interrelated parts:
46
47 1. queueing disciplines manager frontend.
48 2. traffic classes manager frontend.
49
50 Generally, queueing discipline ("qdisc") is a black box,
51 which is able to enqueue packets and to dequeue them (when
52 device is ready to send something) in order and at times
53 determined by algorithm hidden in it.
54
55 qdisc's are divided to two categories:
56 - "queues", which have no internal structure visible from outside.
57 - "schedulers", which split all the packets to "traffic classes",
58 using "packet classifiers" (look at cls_api.c)
59
60 In turn, classes may have child qdiscs (as rule, queues)
61 attached to them etc. etc. etc.
62
63 The goal of the routines in this file is to translate
64 information supplied by user in the form of handles
65 to more intelligible for kernel form, to make some sanity
66 checks and part of work, which is common to all qdiscs
67 and to provide rtnetlink notifications.
68
69 All real intelligent work is done inside qdisc modules.
70
71
72
73 Every discipline has two major routines: enqueue and dequeue.
74
75 ---dequeue
76
77 dequeue usually returns a skb to send. It is allowed to return NULL,
78 but it does not mean that queue is empty, it just means that
79 discipline does not want to send anything this time.
80 Queue is really empty if q->q.qlen == 0.
81 For complicated disciplines with multiple queues q->q is not
82 real packet queue, but however q->q.qlen must be valid.
83
84 ---enqueue
85
86 enqueue returns 0, if packet was enqueued successfully.
87 If packet (this one or another one) was dropped, it returns
88 not zero error code.
89 NET_XMIT_DROP - this packet dropped
90 Expected action: do not backoff, but wait until queue will clear.
91 NET_XMIT_CN - probably this packet enqueued, but another one dropped.
92 Expected action: backoff or ignore
93
94 Auxiliary routines:
95
96 ---peek
97
98 like dequeue but without removing a packet from the queue
99
100 ---reset
101
102 returns qdisc to initial state: purge all buffers, clear all
103 timers, counters (except for statistics) etc.
104
105 ---init
106
107 initializes newly created qdisc.
108
109 ---destroy
110
111 destroys resources allocated by init and during lifetime of qdisc.
112
113 ---change
114
115 changes qdisc parameters.
116 */
117
118/* Protects list of registered TC modules. It is pure SMP lock. */
119static DEFINE_RWLOCK(qdisc_mod_lock);
120
121
122/************************************************
123 * Queueing disciplines manipulation. *
124 ************************************************/
125
126
127/* The list of all installed queueing disciplines. */
128
129static struct Qdisc_ops *qdisc_base;
130
131/* Register/unregister queueing discipline */
132
133int register_qdisc(struct Qdisc_ops *qops)
134{
135 struct Qdisc_ops *q, **qp;
136 int rc = -EEXIST;
137
138 write_lock(&qdisc_mod_lock);
139 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
140 if (!strcmp(qops->id, q->id))
141 goto out;
142
143 if (qops->enqueue == NULL)
144 qops->enqueue = noop_qdisc_ops.enqueue;
145 if (qops->peek == NULL) {
146 if (qops->dequeue == NULL)
147 qops->peek = noop_qdisc_ops.peek;
148 else
149 goto out_einval;
150 }
151 if (qops->dequeue == NULL)
152 qops->dequeue = noop_qdisc_ops.dequeue;
153
154 if (qops->cl_ops) {
155 const struct Qdisc_class_ops *cops = qops->cl_ops;
156
157 if (!(cops->find && cops->walk && cops->leaf))
158 goto out_einval;
159
160 if (cops->tcf_block && !(cops->bind_tcf && cops->unbind_tcf))
161 goto out_einval;
162 }
163
164 qops->next = NULL;
165 *qp = qops;
166 rc = 0;
167out:
168 write_unlock(&qdisc_mod_lock);
169 return rc;
170
171out_einval:
172 rc = -EINVAL;
173 goto out;
174}
175EXPORT_SYMBOL(register_qdisc);
176
177int unregister_qdisc(struct Qdisc_ops *qops)
178{
179 struct Qdisc_ops *q, **qp;
180 int err = -ENOENT;
181
182 write_lock(&qdisc_mod_lock);
183 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
184 if (q == qops)
185 break;
186 if (q) {
187 *qp = q->next;
188 q->next = NULL;
189 err = 0;
190 }
191 write_unlock(&qdisc_mod_lock);
192 return err;
193}
194EXPORT_SYMBOL(unregister_qdisc);
195
196/* Get default qdisc if not otherwise specified */
197void qdisc_get_default(char *name, size_t len)
198{
199 read_lock(&qdisc_mod_lock);
200 strlcpy(name, default_qdisc_ops->id, len);
201 read_unlock(&qdisc_mod_lock);
202}
203
204static struct Qdisc_ops *qdisc_lookup_default(const char *name)
205{
206 struct Qdisc_ops *q = NULL;
207
208 for (q = qdisc_base; q; q = q->next) {
209 if (!strcmp(name, q->id)) {
210 if (!try_module_get(q->owner))
211 q = NULL;
212 break;
213 }
214 }
215
216 return q;
217}
218
219/* Set new default qdisc to use */
220int qdisc_set_default(const char *name)
221{
222 const struct Qdisc_ops *ops;
223
224 if (!capable(CAP_NET_ADMIN))
225 return -EPERM;
226
227 write_lock(&qdisc_mod_lock);
228 ops = qdisc_lookup_default(name);
229 if (!ops) {
230 /* Not found, drop lock and try to load module */
231 write_unlock(&qdisc_mod_lock);
232 request_module("sch_%s", name);
233 write_lock(&qdisc_mod_lock);
234
235 ops = qdisc_lookup_default(name);
236 }
237
238 if (ops) {
239 /* Set new default */
240 module_put(default_qdisc_ops->owner);
241 default_qdisc_ops = ops;
242 }
243 write_unlock(&qdisc_mod_lock);
244
245 return ops ? 0 : -ENOENT;
246}
247
248#ifdef CONFIG_NET_SCH_DEFAULT
249/* Set default value from kernel config */
250static int __init sch_default_qdisc(void)
251{
252 return qdisc_set_default(CONFIG_DEFAULT_NET_SCH);
253}
254late_initcall(sch_default_qdisc);
255#endif
256
257/* We know handle. Find qdisc among all qdisc's attached to device
258 * (root qdisc, all its children, children of children etc.)
259 * Note: caller either uses rtnl or rcu_read_lock()
260 */
261
262static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle)
263{
264 struct Qdisc *q;
265
266 if (!qdisc_dev(root))
267 return (root->handle == handle ? root : NULL);
268
269 if (!(root->flags & TCQ_F_BUILTIN) &&
270 root->handle == handle)
271 return root;
272
273 hash_for_each_possible_rcu(qdisc_dev(root)->qdisc_hash, q, hash, handle) {
274 if (q->handle == handle)
275 return q;
276 }
277 return NULL;
278}
279
280void qdisc_hash_add(struct Qdisc *q, bool invisible)
281{
282 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
283 ASSERT_RTNL();
284 hash_add_rcu(qdisc_dev(q)->qdisc_hash, &q->hash, q->handle);
285 if (invisible)
286 q->flags |= TCQ_F_INVISIBLE;
287 }
288}
289EXPORT_SYMBOL(qdisc_hash_add);
290
291void qdisc_hash_del(struct Qdisc *q)
292{
293 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
294 ASSERT_RTNL();
295 hash_del_rcu(&q->hash);
296 }
297}
298EXPORT_SYMBOL(qdisc_hash_del);
299
300struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
301{
302 struct Qdisc *q;
303
304 if (!handle)
305 return NULL;
306 q = qdisc_match_from_root(dev->qdisc, handle);
307 if (q)
308 goto out;
309
310 if (dev_ingress_queue(dev))
311 q = qdisc_match_from_root(
312 dev_ingress_queue(dev)->qdisc_sleeping,
313 handle);
314out:
315 return q;
316}
317
318static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
319{
320 unsigned long cl;
321 struct Qdisc *leaf;
322 const struct Qdisc_class_ops *cops = p->ops->cl_ops;
323
324 if (cops == NULL)
325 return NULL;
326 cl = cops->find(p, classid);
327
328 if (cl == 0)
329 return NULL;
330 leaf = cops->leaf(p, cl);
331 return leaf;
332}
333
334/* Find queueing discipline by name */
335
336static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind)
337{
338 struct Qdisc_ops *q = NULL;
339
340 if (kind) {
341 read_lock(&qdisc_mod_lock);
342 for (q = qdisc_base; q; q = q->next) {
343 if (nla_strcmp(kind, q->id) == 0) {
344 if (!try_module_get(q->owner))
345 q = NULL;
346 break;
347 }
348 }
349 read_unlock(&qdisc_mod_lock);
350 }
351 return q;
352}
353
354/* The linklayer setting were not transferred from iproute2, in older
355 * versions, and the rate tables lookup systems have been dropped in
356 * the kernel. To keep backward compatible with older iproute2 tc
357 * utils, we detect the linklayer setting by detecting if the rate
358 * table were modified.
359 *
360 * For linklayer ATM table entries, the rate table will be aligned to
361 * 48 bytes, thus some table entries will contain the same value. The
362 * mpu (min packet unit) is also encoded into the old rate table, thus
363 * starting from the mpu, we find low and high table entries for
364 * mapping this cell. If these entries contain the same value, when
365 * the rate tables have been modified for linklayer ATM.
366 *
367 * This is done by rounding mpu to the nearest 48 bytes cell/entry,
368 * and then roundup to the next cell, calc the table entry one below,
369 * and compare.
370 */
371static __u8 __detect_linklayer(struct tc_ratespec *r, __u32 *rtab)
372{
373 int low = roundup(r->mpu, 48);
374 int high = roundup(low+1, 48);
375 int cell_low = low >> r->cell_log;
376 int cell_high = (high >> r->cell_log) - 1;
377
378 /* rtab is too inaccurate at rates > 100Mbit/s */
379 if ((r->rate > (100000000/8)) || (rtab[0] == 0)) {
380 pr_debug("TC linklayer: Giving up ATM detection\n");
381 return TC_LINKLAYER_ETHERNET;
382 }
383
384 if ((cell_high > cell_low) && (cell_high < 256)
385 && (rtab[cell_low] == rtab[cell_high])) {
386 pr_debug("TC linklayer: Detected ATM, low(%d)=high(%d)=%u\n",
387 cell_low, cell_high, rtab[cell_high]);
388 return TC_LINKLAYER_ATM;
389 }
390 return TC_LINKLAYER_ETHERNET;
391}
392
393static struct qdisc_rate_table *qdisc_rtab_list;
394
395struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
396 struct nlattr *tab,
397 struct netlink_ext_ack *extack)
398{
399 struct qdisc_rate_table *rtab;
400
401 if (tab == NULL || r->rate == 0 || r->cell_log == 0 ||
402 nla_len(tab) != TC_RTAB_SIZE) {
403 NL_SET_ERR_MSG(extack, "Invalid rate table parameters for searching");
404 return NULL;
405 }
406
407 for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) {
408 if (!memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) &&
409 !memcmp(&rtab->data, nla_data(tab), 1024)) {
410 rtab->refcnt++;
411 return rtab;
412 }
413 }
414
415 rtab = kmalloc(sizeof(*rtab), GFP_KERNEL);
416 if (rtab) {
417 rtab->rate = *r;
418 rtab->refcnt = 1;
419 memcpy(rtab->data, nla_data(tab), 1024);
420 if (r->linklayer == TC_LINKLAYER_UNAWARE)
421 r->linklayer = __detect_linklayer(r, rtab->data);
422 rtab->next = qdisc_rtab_list;
423 qdisc_rtab_list = rtab;
424 } else {
425 NL_SET_ERR_MSG(extack, "Failed to allocate new qdisc rate table");
426 }
427 return rtab;
428}
429EXPORT_SYMBOL(qdisc_get_rtab);
430
431void qdisc_put_rtab(struct qdisc_rate_table *tab)
432{
433 struct qdisc_rate_table *rtab, **rtabp;
434
435 if (!tab || --tab->refcnt)
436 return;
437
438 for (rtabp = &qdisc_rtab_list;
439 (rtab = *rtabp) != NULL;
440 rtabp = &rtab->next) {
441 if (rtab == tab) {
442 *rtabp = rtab->next;
443 kfree(rtab);
444 return;
445 }
446 }
447}
448EXPORT_SYMBOL(qdisc_put_rtab);
449
450static LIST_HEAD(qdisc_stab_list);
451
452static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = {
453 [TCA_STAB_BASE] = { .len = sizeof(struct tc_sizespec) },
454 [TCA_STAB_DATA] = { .type = NLA_BINARY },
455};
456
457static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt,
458 struct netlink_ext_ack *extack)
459{
460 struct nlattr *tb[TCA_STAB_MAX + 1];
461 struct qdisc_size_table *stab;
462 struct tc_sizespec *s;
463 unsigned int tsize = 0;
464 u16 *tab = NULL;
465 int err;
466
467 err = nla_parse_nested(tb, TCA_STAB_MAX, opt, stab_policy, extack);
468 if (err < 0)
469 return ERR_PTR(err);
470 if (!tb[TCA_STAB_BASE]) {
471 NL_SET_ERR_MSG(extack, "Size table base attribute is missing");
472 return ERR_PTR(-EINVAL);
473 }
474
475 s = nla_data(tb[TCA_STAB_BASE]);
476
477 if (s->tsize > 0) {
478 if (!tb[TCA_STAB_DATA]) {
479 NL_SET_ERR_MSG(extack, "Size table data attribute is missing");
480 return ERR_PTR(-EINVAL);
481 }
482 tab = nla_data(tb[TCA_STAB_DATA]);
483 tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16);
484 }
485
486 if (tsize != s->tsize || (!tab && tsize > 0)) {
487 NL_SET_ERR_MSG(extack, "Invalid size of size table");
488 return ERR_PTR(-EINVAL);
489 }
490
491 list_for_each_entry(stab, &qdisc_stab_list, list) {
492 if (memcmp(&stab->szopts, s, sizeof(*s)))
493 continue;
494 if (tsize > 0 && memcmp(stab->data, tab, tsize * sizeof(u16)))
495 continue;
496 stab->refcnt++;
497 return stab;
498 }
499
500 stab = kmalloc(sizeof(*stab) + tsize * sizeof(u16), GFP_KERNEL);
501 if (!stab)
502 return ERR_PTR(-ENOMEM);
503
504 stab->refcnt = 1;
505 stab->szopts = *s;
506 if (tsize > 0)
507 memcpy(stab->data, tab, tsize * sizeof(u16));
508
509 list_add_tail(&stab->list, &qdisc_stab_list);
510
511 return stab;
512}
513
514static void stab_kfree_rcu(struct rcu_head *head)
515{
516 kfree(container_of(head, struct qdisc_size_table, rcu));
517}
518
519void qdisc_put_stab(struct qdisc_size_table *tab)
520{
521 if (!tab)
522 return;
523
524 if (--tab->refcnt == 0) {
525 list_del(&tab->list);
526 call_rcu_bh(&tab->rcu, stab_kfree_rcu);
527 }
528}
529EXPORT_SYMBOL(qdisc_put_stab);
530
531static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab)
532{
533 struct nlattr *nest;
534
535 nest = nla_nest_start(skb, TCA_STAB);
536 if (nest == NULL)
537 goto nla_put_failure;
538 if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts))
539 goto nla_put_failure;
540 nla_nest_end(skb, nest);
541
542 return skb->len;
543
544nla_put_failure:
545 return -1;
546}
547
548void __qdisc_calculate_pkt_len(struct sk_buff *skb,
549 const struct qdisc_size_table *stab)
550{
551 int pkt_len, slot;
552
553 pkt_len = skb->len + stab->szopts.overhead;
554 if (unlikely(!stab->szopts.tsize))
555 goto out;
556
557 slot = pkt_len + stab->szopts.cell_align;
558 if (unlikely(slot < 0))
559 slot = 0;
560
561 slot >>= stab->szopts.cell_log;
562 if (likely(slot < stab->szopts.tsize))
563 pkt_len = stab->data[slot];
564 else
565 pkt_len = stab->data[stab->szopts.tsize - 1] *
566 (slot / stab->szopts.tsize) +
567 stab->data[slot % stab->szopts.tsize];
568
569 pkt_len <<= stab->szopts.size_log;
570out:
571 if (unlikely(pkt_len < 1))
572 pkt_len = 1;
573 qdisc_skb_cb(skb)->pkt_len = pkt_len;
574}
575EXPORT_SYMBOL(__qdisc_calculate_pkt_len);
576
577void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc)
578{
579 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
580 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n",
581 txt, qdisc->ops->id, qdisc->handle >> 16);
582 qdisc->flags |= TCQ_F_WARN_NONWC;
583 }
584}
585EXPORT_SYMBOL(qdisc_warn_nonwc);
586
587static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
588{
589 struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
590 timer);
591
592 rcu_read_lock();
593 __netif_schedule(qdisc_root(wd->qdisc));
594 rcu_read_unlock();
595
596 return HRTIMER_NORESTART;
597}
598
599void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
600{
601 hrtimer_init(&wd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
602 wd->timer.function = qdisc_watchdog;
603 wd->qdisc = qdisc;
604}
605EXPORT_SYMBOL(qdisc_watchdog_init);
606
607void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires)
608{
609 if (test_bit(__QDISC_STATE_DEACTIVATED,
610 &qdisc_root_sleeping(wd->qdisc)->state))
611 return;
612
613 if (wd->last_expires == expires)
614 return;
615
616 wd->last_expires = expires;
617 hrtimer_start(&wd->timer,
618 ns_to_ktime(expires),
619 HRTIMER_MODE_ABS_PINNED);
620}
621EXPORT_SYMBOL(qdisc_watchdog_schedule_ns);
622
623void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
624{
625 hrtimer_cancel(&wd->timer);
626}
627EXPORT_SYMBOL(qdisc_watchdog_cancel);
628
629static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
630{
631 struct hlist_head *h;
632 unsigned int i;
633
634 h = kvmalloc_array(n, sizeof(struct hlist_head), GFP_KERNEL);
635
636 if (h != NULL) {
637 for (i = 0; i < n; i++)
638 INIT_HLIST_HEAD(&h[i]);
639 }
640 return h;
641}
642
643void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
644{
645 struct Qdisc_class_common *cl;
646 struct hlist_node *next;
647 struct hlist_head *nhash, *ohash;
648 unsigned int nsize, nmask, osize;
649 unsigned int i, h;
650
651 /* Rehash when load factor exceeds 0.75 */
652 if (clhash->hashelems * 4 <= clhash->hashsize * 3)
653 return;
654 nsize = clhash->hashsize * 2;
655 nmask = nsize - 1;
656 nhash = qdisc_class_hash_alloc(nsize);
657 if (nhash == NULL)
658 return;
659
660 ohash = clhash->hash;
661 osize = clhash->hashsize;
662
663 sch_tree_lock(sch);
664 for (i = 0; i < osize; i++) {
665 hlist_for_each_entry_safe(cl, next, &ohash[i], hnode) {
666 h = qdisc_class_hash(cl->classid, nmask);
667 hlist_add_head(&cl->hnode, &nhash[h]);
668 }
669 }
670 clhash->hash = nhash;
671 clhash->hashsize = nsize;
672 clhash->hashmask = nmask;
673 sch_tree_unlock(sch);
674
675 kvfree(ohash);
676}
677EXPORT_SYMBOL(qdisc_class_hash_grow);
678
679int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
680{
681 unsigned int size = 4;
682
683 clhash->hash = qdisc_class_hash_alloc(size);
684 if (!clhash->hash)
685 return -ENOMEM;
686 clhash->hashsize = size;
687 clhash->hashmask = size - 1;
688 clhash->hashelems = 0;
689 return 0;
690}
691EXPORT_SYMBOL(qdisc_class_hash_init);
692
693void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
694{
695 kvfree(clhash->hash);
696}
697EXPORT_SYMBOL(qdisc_class_hash_destroy);
698
699void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
700 struct Qdisc_class_common *cl)
701{
702 unsigned int h;
703
704 INIT_HLIST_NODE(&cl->hnode);
705 h = qdisc_class_hash(cl->classid, clhash->hashmask);
706 hlist_add_head(&cl->hnode, &clhash->hash[h]);
707 clhash->hashelems++;
708}
709EXPORT_SYMBOL(qdisc_class_hash_insert);
710
711void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
712 struct Qdisc_class_common *cl)
713{
714 hlist_del(&cl->hnode);
715 clhash->hashelems--;
716}
717EXPORT_SYMBOL(qdisc_class_hash_remove);
718
719/* Allocate an unique handle from space managed by kernel
720 * Possible range is [8000-FFFF]:0000 (0x8000 values)
721 */
722static u32 qdisc_alloc_handle(struct net_device *dev)
723{
724 int i = 0x8000;
725 static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
726
727 do {
728 autohandle += TC_H_MAKE(0x10000U, 0);
729 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
730 autohandle = TC_H_MAKE(0x80000000U, 0);
731 if (!qdisc_lookup(dev, autohandle))
732 return autohandle;
733 cond_resched();
734 } while (--i > 0);
735
736 return 0;
737}
738
739void qdisc_tree_reduce_backlog(struct Qdisc *sch, unsigned int n,
740 unsigned int len)
741{
742 bool qdisc_is_offloaded = sch->flags & TCQ_F_OFFLOADED;
743 const struct Qdisc_class_ops *cops;
744 unsigned long cl;
745 u32 parentid;
746 bool notify;
747 int drops;
748
749 if (n == 0 && len == 0)
750 return;
751 drops = max_t(int, n, 0);
752 rcu_read_lock();
753 while ((parentid = sch->parent)) {
754 if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
755 break;
756
757 if (sch->flags & TCQ_F_NOPARENT)
758 break;
759 /* Notify parent qdisc only if child qdisc becomes empty.
760 *
761 * If child was empty even before update then backlog
762 * counter is screwed and we skip notification because
763 * parent class is already passive.
764 *
765 * If the original child was offloaded then it is allowed
766 * to be seem as empty, so the parent is notified anyway.
767 */
768 notify = !sch->q.qlen && !WARN_ON_ONCE(!n &&
769 !qdisc_is_offloaded);
770 /* TODO: perform the search on a per txq basis */
771 sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid));
772 if (sch == NULL) {
773 WARN_ON_ONCE(parentid != TC_H_ROOT);
774 break;
775 }
776 cops = sch->ops->cl_ops;
777 if (notify && cops->qlen_notify) {
778 cl = cops->find(sch, parentid);
779 cops->qlen_notify(sch, cl);
780 }
781 sch->q.qlen -= n;
782 sch->qstats.backlog -= len;
783 __qdisc_qstats_drop(sch, drops);
784 }
785 rcu_read_unlock();
786}
787EXPORT_SYMBOL(qdisc_tree_reduce_backlog);
788
789static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
790 u32 portid, u32 seq, u16 flags, int event)
791{
792 struct gnet_stats_basic_cpu __percpu *cpu_bstats = NULL;
793 struct gnet_stats_queue __percpu *cpu_qstats = NULL;
794 struct tcmsg *tcm;
795 struct nlmsghdr *nlh;
796 unsigned char *b = skb_tail_pointer(skb);
797 struct gnet_dump d;
798 struct qdisc_size_table *stab;
799 u32 block_index;
800 __u32 qlen;
801
802 cond_resched();
803 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
804 if (!nlh)
805 goto out_nlmsg_trim;
806 tcm = nlmsg_data(nlh);
807 tcm->tcm_family = AF_UNSPEC;
808 tcm->tcm__pad1 = 0;
809 tcm->tcm__pad2 = 0;
810 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
811 tcm->tcm_parent = clid;
812 tcm->tcm_handle = q->handle;
813 tcm->tcm_info = refcount_read(&q->refcnt);
814 if (nla_put_string(skb, TCA_KIND, q->ops->id))
815 goto nla_put_failure;
816 if (q->ops->ingress_block_get) {
817 block_index = q->ops->ingress_block_get(q);
818 if (block_index &&
819 nla_put_u32(skb, TCA_INGRESS_BLOCK, block_index))
820 goto nla_put_failure;
821 }
822 if (q->ops->egress_block_get) {
823 block_index = q->ops->egress_block_get(q);
824 if (block_index &&
825 nla_put_u32(skb, TCA_EGRESS_BLOCK, block_index))
826 goto nla_put_failure;
827 }
828 if (q->ops->dump && q->ops->dump(q, skb) < 0)
829 goto nla_put_failure;
830 if (nla_put_u8(skb, TCA_HW_OFFLOAD, !!(q->flags & TCQ_F_OFFLOADED)))
831 goto nla_put_failure;
832 qlen = qdisc_qlen_sum(q);
833
834 stab = rtnl_dereference(q->stab);
835 if (stab && qdisc_dump_stab(skb, stab) < 0)
836 goto nla_put_failure;
837
838 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
839 NULL, &d, TCA_PAD) < 0)
840 goto nla_put_failure;
841
842 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
843 goto nla_put_failure;
844
845 if (qdisc_is_percpu_stats(q)) {
846 cpu_bstats = q->cpu_bstats;
847 cpu_qstats = q->cpu_qstats;
848 }
849
850 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(q),
851 &d, cpu_bstats, &q->bstats) < 0 ||
852 gnet_stats_copy_rate_est(&d, &q->rate_est) < 0 ||
853 gnet_stats_copy_queue(&d, cpu_qstats, &q->qstats, qlen) < 0)
854 goto nla_put_failure;
855
856 if (gnet_stats_finish_copy(&d) < 0)
857 goto nla_put_failure;
858
859 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
860 return skb->len;
861
862out_nlmsg_trim:
863nla_put_failure:
864 nlmsg_trim(skb, b);
865 return -1;
866}
867
868static bool tc_qdisc_dump_ignore(struct Qdisc *q, bool dump_invisible)
869{
870 if (q->flags & TCQ_F_BUILTIN)
871 return true;
872 if ((q->flags & TCQ_F_INVISIBLE) && !dump_invisible)
873 return true;
874
875 return false;
876}
877
878static int qdisc_notify(struct net *net, struct sk_buff *oskb,
879 struct nlmsghdr *n, u32 clid,
880 struct Qdisc *old, struct Qdisc *new)
881{
882 struct sk_buff *skb;
883 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
884
885 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
886 if (!skb)
887 return -ENOBUFS;
888
889 if (old && !tc_qdisc_dump_ignore(old, false)) {
890 if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq,
891 0, RTM_DELQDISC) < 0)
892 goto err_out;
893 }
894 if (new && !tc_qdisc_dump_ignore(new, false)) {
895 if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq,
896 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
897 goto err_out;
898 }
899
900 if (skb->len)
901 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
902 n->nlmsg_flags & NLM_F_ECHO);
903
904err_out:
905 kfree_skb(skb);
906 return -EINVAL;
907}
908
909static void notify_and_destroy(struct net *net, struct sk_buff *skb,
910 struct nlmsghdr *n, u32 clid,
911 struct Qdisc *old, struct Qdisc *new)
912{
913 if (new || old)
914 qdisc_notify(net, skb, n, clid, old, new);
915
916 if (old)
917 qdisc_destroy(old);
918}
919
920/* Graft qdisc "new" to class "classid" of qdisc "parent" or
921 * to device "dev".
922 *
923 * When appropriate send a netlink notification using 'skb'
924 * and "n".
925 *
926 * On success, destroy old qdisc.
927 */
928
929static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
930 struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
931 struct Qdisc *new, struct Qdisc *old,
932 struct netlink_ext_ack *extack)
933{
934 struct Qdisc *q = old;
935 struct net *net = dev_net(dev);
936 int err = 0;
937
938 if (parent == NULL) {
939 unsigned int i, num_q, ingress;
940
941 ingress = 0;
942 num_q = dev->num_tx_queues;
943 if ((q && q->flags & TCQ_F_INGRESS) ||
944 (new && new->flags & TCQ_F_INGRESS)) {
945 num_q = 1;
946 ingress = 1;
947 if (!dev_ingress_queue(dev)) {
948 NL_SET_ERR_MSG(extack, "Device does not have an ingress queue");
949 return -ENOENT;
950 }
951 }
952
953 if (dev->flags & IFF_UP)
954 dev_deactivate(dev);
955
956 if (new && new->ops->attach)
957 goto skip;
958
959 for (i = 0; i < num_q; i++) {
960 struct netdev_queue *dev_queue = dev_ingress_queue(dev);
961
962 if (!ingress)
963 dev_queue = netdev_get_tx_queue(dev, i);
964
965 old = dev_graft_qdisc(dev_queue, new);
966 if (new && i > 0)
967 qdisc_refcount_inc(new);
968
969 if (!ingress)
970 qdisc_destroy(old);
971 }
972
973skip:
974 if (!ingress) {
975 notify_and_destroy(net, skb, n, classid,
976 dev->qdisc, new);
977 if (new && !new->ops->attach)
978 qdisc_refcount_inc(new);
979 dev->qdisc = new ? : &noop_qdisc;
980
981 if (new && new->ops->attach)
982 new->ops->attach(new);
983 } else {
984 notify_and_destroy(net, skb, n, classid, old, new);
985 }
986
987 if (dev->flags & IFF_UP)
988 dev_activate(dev);
989 } else {
990 const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
991
992 /* Only support running class lockless if parent is lockless */
993 if (new && (new->flags & TCQ_F_NOLOCK) &&
994 parent && !(parent->flags & TCQ_F_NOLOCK))
995 new->flags &= ~TCQ_F_NOLOCK;
996
997 err = -EOPNOTSUPP;
998 if (cops && cops->graft) {
999 unsigned long cl = cops->find(parent, classid);
1000
1001 if (cl) {
1002 err = cops->graft(parent, cl, new, &old,
1003 extack);
1004 } else {
1005 NL_SET_ERR_MSG(extack, "Specified class not found");
1006 err = -ENOENT;
1007 }
1008 }
1009 if (!err)
1010 notify_and_destroy(net, skb, n, classid, old, new);
1011 }
1012 return err;
1013}
1014
1015static int qdisc_block_indexes_set(struct Qdisc *sch, struct nlattr **tca,
1016 struct netlink_ext_ack *extack)
1017{
1018 u32 block_index;
1019
1020 if (tca[TCA_INGRESS_BLOCK]) {
1021 block_index = nla_get_u32(tca[TCA_INGRESS_BLOCK]);
1022
1023 if (!block_index) {
1024 NL_SET_ERR_MSG(extack, "Ingress block index cannot be 0");
1025 return -EINVAL;
1026 }
1027 if (!sch->ops->ingress_block_set) {
1028 NL_SET_ERR_MSG(extack, "Ingress block sharing is not supported");
1029 return -EOPNOTSUPP;
1030 }
1031 sch->ops->ingress_block_set(sch, block_index);
1032 }
1033 if (tca[TCA_EGRESS_BLOCK]) {
1034 block_index = nla_get_u32(tca[TCA_EGRESS_BLOCK]);
1035
1036 if (!block_index) {
1037 NL_SET_ERR_MSG(extack, "Egress block index cannot be 0");
1038 return -EINVAL;
1039 }
1040 if (!sch->ops->egress_block_set) {
1041 NL_SET_ERR_MSG(extack, "Egress block sharing is not supported");
1042 return -EOPNOTSUPP;
1043 }
1044 sch->ops->egress_block_set(sch, block_index);
1045 }
1046 return 0;
1047}
1048
1049/* lockdep annotation is needed for ingress; egress gets it only for name */
1050static struct lock_class_key qdisc_tx_lock;
1051static struct lock_class_key qdisc_rx_lock;
1052
1053/*
1054 Allocate and initialize new qdisc.
1055
1056 Parameters are passed via opt.
1057 */
1058
1059static struct Qdisc *qdisc_create(struct net_device *dev,
1060 struct netdev_queue *dev_queue,
1061 struct Qdisc *p, u32 parent, u32 handle,
1062 struct nlattr **tca, int *errp,
1063 struct netlink_ext_ack *extack)
1064{
1065 int err;
1066 struct nlattr *kind = tca[TCA_KIND];
1067 struct Qdisc *sch;
1068 struct Qdisc_ops *ops;
1069 struct qdisc_size_table *stab;
1070
1071 ops = qdisc_lookup_ops(kind);
1072#ifdef CONFIG_MODULES
1073 if (ops == NULL && kind != NULL) {
1074 char name[IFNAMSIZ];
1075 if (nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
1076 /* We dropped the RTNL semaphore in order to
1077 * perform the module load. So, even if we
1078 * succeeded in loading the module we have to
1079 * tell the caller to replay the request. We
1080 * indicate this using -EAGAIN.
1081 * We replay the request because the device may
1082 * go away in the mean time.
1083 */
1084 rtnl_unlock();
1085 request_module("sch_%s", name);
1086 rtnl_lock();
1087 ops = qdisc_lookup_ops(kind);
1088 if (ops != NULL) {
1089 /* We will try again qdisc_lookup_ops,
1090 * so don't keep a reference.
1091 */
1092 module_put(ops->owner);
1093 err = -EAGAIN;
1094 goto err_out;
1095 }
1096 }
1097 }
1098#endif
1099
1100 err = -ENOENT;
1101 if (!ops) {
1102 NL_SET_ERR_MSG(extack, "Specified qdisc not found");
1103 goto err_out;
1104 }
1105
1106 sch = qdisc_alloc(dev_queue, ops, extack);
1107 if (IS_ERR(sch)) {
1108 err = PTR_ERR(sch);
1109 goto err_out2;
1110 }
1111
1112 sch->parent = parent;
1113
1114 if (handle == TC_H_INGRESS) {
1115 sch->flags |= TCQ_F_INGRESS;
1116 handle = TC_H_MAKE(TC_H_INGRESS, 0);
1117 lockdep_set_class(qdisc_lock(sch), &qdisc_rx_lock);
1118 } else {
1119 if (handle == 0) {
1120 handle = qdisc_alloc_handle(dev);
1121 err = -ENOMEM;
1122 if (handle == 0)
1123 goto err_out3;
1124 }
1125 lockdep_set_class(qdisc_lock(sch), &qdisc_tx_lock);
1126 if (!netif_is_multiqueue(dev))
1127 sch->flags |= TCQ_F_ONETXQUEUE;
1128 }
1129
1130 sch->handle = handle;
1131
1132 /* This exist to keep backward compatible with a userspace
1133 * loophole, what allowed userspace to get IFF_NO_QUEUE
1134 * facility on older kernels by setting tx_queue_len=0 (prior
1135 * to qdisc init), and then forgot to reinit tx_queue_len
1136 * before again attaching a qdisc.
1137 */
1138 if ((dev->priv_flags & IFF_NO_QUEUE) && (dev->tx_queue_len == 0)) {
1139 dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
1140 netdev_info(dev, "Caught tx_queue_len zero misconfig\n");
1141 }
1142
1143 err = qdisc_block_indexes_set(sch, tca, extack);
1144 if (err)
1145 goto err_out3;
1146
1147 if (ops->init) {
1148 err = ops->init(sch, tca[TCA_OPTIONS], extack);
1149 if (err != 0)
1150 goto err_out5;
1151 }
1152
1153 if (tca[TCA_STAB]) {
1154 stab = qdisc_get_stab(tca[TCA_STAB], extack);
1155 if (IS_ERR(stab)) {
1156 err = PTR_ERR(stab);
1157 goto err_out4;
1158 }
1159 rcu_assign_pointer(sch->stab, stab);
1160 }
1161 if (tca[TCA_RATE]) {
1162 seqcount_t *running;
1163
1164 err = -EOPNOTSUPP;
1165 if (sch->flags & TCQ_F_MQROOT) {
1166 NL_SET_ERR_MSG(extack, "Cannot attach rate estimator to a multi-queue root qdisc");
1167 goto err_out4;
1168 }
1169
1170 if (sch->parent != TC_H_ROOT &&
1171 !(sch->flags & TCQ_F_INGRESS) &&
1172 (!p || !(p->flags & TCQ_F_MQROOT)))
1173 running = qdisc_root_sleeping_running(sch);
1174 else
1175 running = &sch->running;
1176
1177 err = gen_new_estimator(&sch->bstats,
1178 sch->cpu_bstats,
1179 &sch->rate_est,
1180 NULL,
1181 running,
1182 tca[TCA_RATE]);
1183 if (err) {
1184 NL_SET_ERR_MSG(extack, "Failed to generate new estimator");
1185 goto err_out4;
1186 }
1187 }
1188
1189 qdisc_hash_add(sch, false);
1190
1191 return sch;
1192
1193err_out5:
1194 /* ops->init() failed, we call ->destroy() like qdisc_create_dflt() */
1195 if (ops->destroy)
1196 ops->destroy(sch);
1197err_out3:
1198 dev_put(dev);
1199 qdisc_free(sch);
1200err_out2:
1201 module_put(ops->owner);
1202err_out:
1203 *errp = err;
1204 return NULL;
1205
1206err_out4:
1207 /*
1208 * Any broken qdiscs that would require a ops->reset() here?
1209 * The qdisc was never in action so it shouldn't be necessary.
1210 */
1211 qdisc_put_stab(rtnl_dereference(sch->stab));
1212 if (ops->destroy)
1213 ops->destroy(sch);
1214 goto err_out3;
1215}
1216
1217static int qdisc_change(struct Qdisc *sch, struct nlattr **tca,
1218 struct netlink_ext_ack *extack)
1219{
1220 struct qdisc_size_table *ostab, *stab = NULL;
1221 int err = 0;
1222
1223 if (tca[TCA_OPTIONS]) {
1224 if (!sch->ops->change) {
1225 NL_SET_ERR_MSG(extack, "Change operation not supported by specified qdisc");
1226 return -EINVAL;
1227 }
1228 if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) {
1229 NL_SET_ERR_MSG(extack, "Change of blocks is not supported");
1230 return -EOPNOTSUPP;
1231 }
1232 err = sch->ops->change(sch, tca[TCA_OPTIONS], extack);
1233 if (err)
1234 return err;
1235 }
1236
1237 if (tca[TCA_STAB]) {
1238 stab = qdisc_get_stab(tca[TCA_STAB], extack);
1239 if (IS_ERR(stab))
1240 return PTR_ERR(stab);
1241 }
1242
1243 ostab = rtnl_dereference(sch->stab);
1244 rcu_assign_pointer(sch->stab, stab);
1245 qdisc_put_stab(ostab);
1246
1247 if (tca[TCA_RATE]) {
1248 /* NB: ignores errors from replace_estimator
1249 because change can't be undone. */
1250 if (sch->flags & TCQ_F_MQROOT)
1251 goto out;
1252 gen_replace_estimator(&sch->bstats,
1253 sch->cpu_bstats,
1254 &sch->rate_est,
1255 NULL,
1256 qdisc_root_sleeping_running(sch),
1257 tca[TCA_RATE]);
1258 }
1259out:
1260 return 0;
1261}
1262
1263struct check_loop_arg {
1264 struct qdisc_walker w;
1265 struct Qdisc *p;
1266 int depth;
1267};
1268
1269static int check_loop_fn(struct Qdisc *q, unsigned long cl,
1270 struct qdisc_walker *w);
1271
1272static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
1273{
1274 struct check_loop_arg arg;
1275
1276 if (q->ops->cl_ops == NULL)
1277 return 0;
1278
1279 arg.w.stop = arg.w.skip = arg.w.count = 0;
1280 arg.w.fn = check_loop_fn;
1281 arg.depth = depth;
1282 arg.p = p;
1283 q->ops->cl_ops->walk(q, &arg.w);
1284 return arg.w.stop ? -ELOOP : 0;
1285}
1286
1287static int
1288check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
1289{
1290 struct Qdisc *leaf;
1291 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1292 struct check_loop_arg *arg = (struct check_loop_arg *)w;
1293
1294 leaf = cops->leaf(q, cl);
1295 if (leaf) {
1296 if (leaf == arg->p || arg->depth > 7)
1297 return -ELOOP;
1298 return check_loop(leaf, arg->p, arg->depth + 1);
1299 }
1300 return 0;
1301}
1302
1303/*
1304 * Delete/get qdisc.
1305 */
1306
1307static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
1308 struct netlink_ext_ack *extack)
1309{
1310 struct net *net = sock_net(skb->sk);
1311 struct tcmsg *tcm = nlmsg_data(n);
1312 struct nlattr *tca[TCA_MAX + 1];
1313 struct net_device *dev;
1314 u32 clid;
1315 struct Qdisc *q = NULL;
1316 struct Qdisc *p = NULL;
1317 int err;
1318
1319 if ((n->nlmsg_type != RTM_GETQDISC) &&
1320 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1321 return -EPERM;
1322
1323 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL, extack);
1324 if (err < 0)
1325 return err;
1326
1327 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1328 if (!dev)
1329 return -ENODEV;
1330
1331 clid = tcm->tcm_parent;
1332 if (clid) {
1333 if (clid != TC_H_ROOT) {
1334 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
1335 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1336 if (!p) {
1337 NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified classid");
1338 return -ENOENT;
1339 }
1340 q = qdisc_leaf(p, clid);
1341 } else if (dev_ingress_queue(dev)) {
1342 q = dev_ingress_queue(dev)->qdisc_sleeping;
1343 }
1344 } else {
1345 q = dev->qdisc;
1346 }
1347 if (!q) {
1348 NL_SET_ERR_MSG(extack, "Cannot find specified qdisc on specified device");
1349 return -ENOENT;
1350 }
1351
1352 if (tcm->tcm_handle && q->handle != tcm->tcm_handle) {
1353 NL_SET_ERR_MSG(extack, "Invalid handle");
1354 return -EINVAL;
1355 }
1356 } else {
1357 q = qdisc_lookup(dev, tcm->tcm_handle);
1358 if (!q) {
1359 NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified handle");
1360 return -ENOENT;
1361 }
1362 }
1363
1364 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1365 NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1366 return -EINVAL;
1367 }
1368
1369 if (n->nlmsg_type == RTM_DELQDISC) {
1370 if (!clid) {
1371 NL_SET_ERR_MSG(extack, "Classid cannot be zero");
1372 return -EINVAL;
1373 }
1374 if (q->handle == 0) {
1375 NL_SET_ERR_MSG(extack, "Cannot delete qdisc with handle of zero");
1376 return -ENOENT;
1377 }
1378 err = qdisc_graft(dev, p, skb, n, clid, NULL, q, extack);
1379 if (err != 0)
1380 return err;
1381 } else {
1382 qdisc_notify(net, skb, n, clid, NULL, q);
1383 }
1384 return 0;
1385}
1386
1387/*
1388 * Create/change qdisc.
1389 */
1390
1391static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
1392 struct netlink_ext_ack *extack)
1393{
1394 struct net *net = sock_net(skb->sk);
1395 struct tcmsg *tcm;
1396 struct nlattr *tca[TCA_MAX + 1];
1397 struct net_device *dev;
1398 u32 clid;
1399 struct Qdisc *q, *p;
1400 int err;
1401
1402 if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1403 return -EPERM;
1404
1405replay:
1406 /* Reinit, just in case something touches this. */
1407 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL, extack);
1408 if (err < 0)
1409 return err;
1410
1411 tcm = nlmsg_data(n);
1412 clid = tcm->tcm_parent;
1413 q = p = NULL;
1414
1415 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1416 if (!dev)
1417 return -ENODEV;
1418
1419
1420 if (clid) {
1421 if (clid != TC_H_ROOT) {
1422 if (clid != TC_H_INGRESS) {
1423 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1424 if (!p) {
1425 NL_SET_ERR_MSG(extack, "Failed to find specified qdisc");
1426 return -ENOENT;
1427 }
1428 q = qdisc_leaf(p, clid);
1429 } else if (dev_ingress_queue_create(dev)) {
1430 q = dev_ingress_queue(dev)->qdisc_sleeping;
1431 }
1432 } else {
1433 q = dev->qdisc;
1434 }
1435
1436 /* It may be default qdisc, ignore it */
1437 if (q && q->handle == 0)
1438 q = NULL;
1439
1440 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1441 if (tcm->tcm_handle) {
1442 if (q && !(n->nlmsg_flags & NLM_F_REPLACE)) {
1443 NL_SET_ERR_MSG(extack, "NLM_F_REPLACE needed to override");
1444 return -EEXIST;
1445 }
1446 if (TC_H_MIN(tcm->tcm_handle)) {
1447 NL_SET_ERR_MSG(extack, "Invalid minor handle");
1448 return -EINVAL;
1449 }
1450 q = qdisc_lookup(dev, tcm->tcm_handle);
1451 if (!q)
1452 goto create_n_graft;
1453 if (n->nlmsg_flags & NLM_F_EXCL) {
1454 NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot override");
1455 return -EEXIST;
1456 }
1457 if (tca[TCA_KIND] &&
1458 nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1459 NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1460 return -EINVAL;
1461 }
1462 if (q == p ||
1463 (p && check_loop(q, p, 0))) {
1464 NL_SET_ERR_MSG(extack, "Qdisc parent/child loop detected");
1465 return -ELOOP;
1466 }
1467 qdisc_refcount_inc(q);
1468 goto graft;
1469 } else {
1470 if (!q)
1471 goto create_n_graft;
1472
1473 /* This magic test requires explanation.
1474 *
1475 * We know, that some child q is already
1476 * attached to this parent and have choice:
1477 * either to change it or to create/graft new one.
1478 *
1479 * 1. We are allowed to create/graft only
1480 * if CREATE and REPLACE flags are set.
1481 *
1482 * 2. If EXCL is set, requestor wanted to say,
1483 * that qdisc tcm_handle is not expected
1484 * to exist, so that we choose create/graft too.
1485 *
1486 * 3. The last case is when no flags are set.
1487 * Alas, it is sort of hole in API, we
1488 * cannot decide what to do unambiguously.
1489 * For now we select create/graft, if
1490 * user gave KIND, which does not match existing.
1491 */
1492 if ((n->nlmsg_flags & NLM_F_CREATE) &&
1493 (n->nlmsg_flags & NLM_F_REPLACE) &&
1494 ((n->nlmsg_flags & NLM_F_EXCL) ||
1495 (tca[TCA_KIND] &&
1496 nla_strcmp(tca[TCA_KIND], q->ops->id))))
1497 goto create_n_graft;
1498 }
1499 }
1500 } else {
1501 if (!tcm->tcm_handle) {
1502 NL_SET_ERR_MSG(extack, "Handle cannot be zero");
1503 return -EINVAL;
1504 }
1505 q = qdisc_lookup(dev, tcm->tcm_handle);
1506 }
1507
1508 /* Change qdisc parameters */
1509 if (!q) {
1510 NL_SET_ERR_MSG(extack, "Specified qdisc not found");
1511 return -ENOENT;
1512 }
1513 if (n->nlmsg_flags & NLM_F_EXCL) {
1514 NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot modify");
1515 return -EEXIST;
1516 }
1517 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1518 NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1519 return -EINVAL;
1520 }
1521 err = qdisc_change(q, tca, extack);
1522 if (err == 0)
1523 qdisc_notify(net, skb, n, clid, NULL, q);
1524 return err;
1525
1526create_n_graft:
1527 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
1528 NL_SET_ERR_MSG(extack, "Qdisc not found. To create specify NLM_F_CREATE flag");
1529 return -ENOENT;
1530 }
1531 if (clid == TC_H_INGRESS) {
1532 if (dev_ingress_queue(dev)) {
1533 q = qdisc_create(dev, dev_ingress_queue(dev), p,
1534 tcm->tcm_parent, tcm->tcm_parent,
1535 tca, &err, extack);
1536 } else {
1537 NL_SET_ERR_MSG(extack, "Cannot find ingress queue for specified device");
1538 err = -ENOENT;
1539 }
1540 } else {
1541 struct netdev_queue *dev_queue;
1542
1543 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1544 dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1545 else if (p)
1546 dev_queue = p->dev_queue;
1547 else
1548 dev_queue = netdev_get_tx_queue(dev, 0);
1549
1550 q = qdisc_create(dev, dev_queue, p,
1551 tcm->tcm_parent, tcm->tcm_handle,
1552 tca, &err, extack);
1553 }
1554 if (q == NULL) {
1555 if (err == -EAGAIN)
1556 goto replay;
1557 return err;
1558 }
1559
1560graft:
1561 err = qdisc_graft(dev, p, skb, n, clid, q, NULL, extack);
1562 if (err) {
1563 if (q)
1564 qdisc_destroy(q);
1565 return err;
1566 }
1567
1568 return 0;
1569}
1570
1571static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1572 struct netlink_callback *cb,
1573 int *q_idx_p, int s_q_idx, bool recur,
1574 bool dump_invisible)
1575{
1576 int ret = 0, q_idx = *q_idx_p;
1577 struct Qdisc *q;
1578 int b;
1579
1580 if (!root)
1581 return 0;
1582
1583 q = root;
1584 if (q_idx < s_q_idx) {
1585 q_idx++;
1586 } else {
1587 if (!tc_qdisc_dump_ignore(q, dump_invisible) &&
1588 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1589 cb->nlh->nlmsg_seq, NLM_F_MULTI,
1590 RTM_NEWQDISC) <= 0)
1591 goto done;
1592 q_idx++;
1593 }
1594
1595 /* If dumping singletons, there is no qdisc_dev(root) and the singleton
1596 * itself has already been dumped.
1597 *
1598 * If we've already dumped the top-level (ingress) qdisc above and the global
1599 * qdisc hashtable, we don't want to hit it again
1600 */
1601 if (!qdisc_dev(root) || !recur)
1602 goto out;
1603
1604 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
1605 if (q_idx < s_q_idx) {
1606 q_idx++;
1607 continue;
1608 }
1609 if (!tc_qdisc_dump_ignore(q, dump_invisible) &&
1610 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1611 cb->nlh->nlmsg_seq, NLM_F_MULTI,
1612 RTM_NEWQDISC) <= 0)
1613 goto done;
1614 q_idx++;
1615 }
1616
1617out:
1618 *q_idx_p = q_idx;
1619 return ret;
1620done:
1621 ret = -1;
1622 goto out;
1623}
1624
1625static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1626{
1627 struct net *net = sock_net(skb->sk);
1628 int idx, q_idx;
1629 int s_idx, s_q_idx;
1630 struct net_device *dev;
1631 const struct nlmsghdr *nlh = cb->nlh;
1632 struct nlattr *tca[TCA_MAX + 1];
1633 int err;
1634
1635 s_idx = cb->args[0];
1636 s_q_idx = q_idx = cb->args[1];
1637
1638 idx = 0;
1639 ASSERT_RTNL();
1640
1641 err = nlmsg_parse(nlh, sizeof(struct tcmsg), tca, TCA_MAX, NULL, NULL);
1642 if (err < 0)
1643 return err;
1644
1645 for_each_netdev(net, dev) {
1646 struct netdev_queue *dev_queue;
1647
1648 if (idx < s_idx)
1649 goto cont;
1650 if (idx > s_idx)
1651 s_q_idx = 0;
1652 q_idx = 0;
1653
1654 if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx,
1655 true, tca[TCA_DUMP_INVISIBLE]) < 0)
1656 goto done;
1657
1658 dev_queue = dev_ingress_queue(dev);
1659 if (dev_queue &&
1660 tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb,
1661 &q_idx, s_q_idx, false,
1662 tca[TCA_DUMP_INVISIBLE]) < 0)
1663 goto done;
1664
1665cont:
1666 idx++;
1667 }
1668
1669done:
1670 cb->args[0] = idx;
1671 cb->args[1] = q_idx;
1672
1673 return skb->len;
1674}
1675
1676
1677
1678/************************************************
1679 * Traffic classes manipulation. *
1680 ************************************************/
1681
1682static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1683 unsigned long cl,
1684 u32 portid, u32 seq, u16 flags, int event)
1685{
1686 struct tcmsg *tcm;
1687 struct nlmsghdr *nlh;
1688 unsigned char *b = skb_tail_pointer(skb);
1689 struct gnet_dump d;
1690 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1691
1692 cond_resched();
1693 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1694 if (!nlh)
1695 goto out_nlmsg_trim;
1696 tcm = nlmsg_data(nlh);
1697 tcm->tcm_family = AF_UNSPEC;
1698 tcm->tcm__pad1 = 0;
1699 tcm->tcm__pad2 = 0;
1700 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1701 tcm->tcm_parent = q->handle;
1702 tcm->tcm_handle = q->handle;
1703 tcm->tcm_info = 0;
1704 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1705 goto nla_put_failure;
1706 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1707 goto nla_put_failure;
1708
1709 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1710 NULL, &d, TCA_PAD) < 0)
1711 goto nla_put_failure;
1712
1713 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1714 goto nla_put_failure;
1715
1716 if (gnet_stats_finish_copy(&d) < 0)
1717 goto nla_put_failure;
1718
1719 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1720 return skb->len;
1721
1722out_nlmsg_trim:
1723nla_put_failure:
1724 nlmsg_trim(skb, b);
1725 return -1;
1726}
1727
1728static int tclass_notify(struct net *net, struct sk_buff *oskb,
1729 struct nlmsghdr *n, struct Qdisc *q,
1730 unsigned long cl, int event)
1731{
1732 struct sk_buff *skb;
1733 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1734
1735 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1736 if (!skb)
1737 return -ENOBUFS;
1738
1739 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event) < 0) {
1740 kfree_skb(skb);
1741 return -EINVAL;
1742 }
1743
1744 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1745 n->nlmsg_flags & NLM_F_ECHO);
1746}
1747
1748static int tclass_del_notify(struct net *net,
1749 const struct Qdisc_class_ops *cops,
1750 struct sk_buff *oskb, struct nlmsghdr *n,
1751 struct Qdisc *q, unsigned long cl)
1752{
1753 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1754 struct sk_buff *skb;
1755 int err = 0;
1756
1757 if (!cops->delete)
1758 return -EOPNOTSUPP;
1759
1760 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1761 if (!skb)
1762 return -ENOBUFS;
1763
1764 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0,
1765 RTM_DELTCLASS) < 0) {
1766 kfree_skb(skb);
1767 return -EINVAL;
1768 }
1769
1770 err = cops->delete(q, cl);
1771 if (err) {
1772 kfree_skb(skb);
1773 return err;
1774 }
1775
1776 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1777 n->nlmsg_flags & NLM_F_ECHO);
1778}
1779
1780#ifdef CONFIG_NET_CLS
1781
1782struct tcf_bind_args {
1783 struct tcf_walker w;
1784 u32 classid;
1785 unsigned long cl;
1786};
1787
1788static int tcf_node_bind(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
1789{
1790 struct tcf_bind_args *a = (void *)arg;
1791
1792 if (tp->ops->bind_class) {
1793 struct Qdisc *q = tcf_block_q(tp->chain->block);
1794
1795 sch_tree_lock(q);
1796 tp->ops->bind_class(n, a->classid, a->cl);
1797 sch_tree_unlock(q);
1798 }
1799 return 0;
1800}
1801
1802static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
1803 unsigned long new_cl)
1804{
1805 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1806 struct tcf_block *block;
1807 struct tcf_chain *chain;
1808 unsigned long cl;
1809
1810 cl = cops->find(q, portid);
1811 if (!cl)
1812 return;
1813 block = cops->tcf_block(q, cl, NULL);
1814 if (!block)
1815 return;
1816 list_for_each_entry(chain, &block->chain_list, list) {
1817 struct tcf_proto *tp;
1818
1819 for (tp = rtnl_dereference(chain->filter_chain);
1820 tp; tp = rtnl_dereference(tp->next)) {
1821 struct tcf_bind_args arg = {};
1822
1823 arg.w.fn = tcf_node_bind;
1824 arg.classid = clid;
1825 arg.cl = new_cl;
1826 tp->ops->walk(tp, &arg.w);
1827 }
1828 }
1829}
1830
1831#else
1832
1833static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
1834 unsigned long new_cl)
1835{
1836}
1837
1838#endif
1839
1840static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n,
1841 struct netlink_ext_ack *extack)
1842{
1843 struct net *net = sock_net(skb->sk);
1844 struct tcmsg *tcm = nlmsg_data(n);
1845 struct nlattr *tca[TCA_MAX + 1];
1846 struct net_device *dev;
1847 struct Qdisc *q = NULL;
1848 const struct Qdisc_class_ops *cops;
1849 unsigned long cl = 0;
1850 unsigned long new_cl;
1851 u32 portid;
1852 u32 clid;
1853 u32 qid;
1854 int err;
1855
1856 if ((n->nlmsg_type != RTM_GETTCLASS) &&
1857 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1858 return -EPERM;
1859
1860 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL, extack);
1861 if (err < 0)
1862 return err;
1863
1864 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1865 if (!dev)
1866 return -ENODEV;
1867
1868 /*
1869 parent == TC_H_UNSPEC - unspecified parent.
1870 parent == TC_H_ROOT - class is root, which has no parent.
1871 parent == X:0 - parent is root class.
1872 parent == X:Y - parent is a node in hierarchy.
1873 parent == 0:Y - parent is X:Y, where X:0 is qdisc.
1874
1875 handle == 0:0 - generate handle from kernel pool.
1876 handle == 0:Y - class is X:Y, where X:0 is qdisc.
1877 handle == X:Y - clear.
1878 handle == X:0 - root class.
1879 */
1880
1881 /* Step 1. Determine qdisc handle X:0 */
1882
1883 portid = tcm->tcm_parent;
1884 clid = tcm->tcm_handle;
1885 qid = TC_H_MAJ(clid);
1886
1887 if (portid != TC_H_ROOT) {
1888 u32 qid1 = TC_H_MAJ(portid);
1889
1890 if (qid && qid1) {
1891 /* If both majors are known, they must be identical. */
1892 if (qid != qid1)
1893 return -EINVAL;
1894 } else if (qid1) {
1895 qid = qid1;
1896 } else if (qid == 0)
1897 qid = dev->qdisc->handle;
1898
1899 /* Now qid is genuine qdisc handle consistent
1900 * both with parent and child.
1901 *
1902 * TC_H_MAJ(portid) still may be unspecified, complete it now.
1903 */
1904 if (portid)
1905 portid = TC_H_MAKE(qid, portid);
1906 } else {
1907 if (qid == 0)
1908 qid = dev->qdisc->handle;
1909 }
1910
1911 /* OK. Locate qdisc */
1912 q = qdisc_lookup(dev, qid);
1913 if (!q)
1914 return -ENOENT;
1915
1916 /* An check that it supports classes */
1917 cops = q->ops->cl_ops;
1918 if (cops == NULL)
1919 return -EINVAL;
1920
1921 /* Now try to get class */
1922 if (clid == 0) {
1923 if (portid == TC_H_ROOT)
1924 clid = qid;
1925 } else
1926 clid = TC_H_MAKE(qid, clid);
1927
1928 if (clid)
1929 cl = cops->find(q, clid);
1930
1931 if (cl == 0) {
1932 err = -ENOENT;
1933 if (n->nlmsg_type != RTM_NEWTCLASS ||
1934 !(n->nlmsg_flags & NLM_F_CREATE))
1935 goto out;
1936 } else {
1937 switch (n->nlmsg_type) {
1938 case RTM_NEWTCLASS:
1939 err = -EEXIST;
1940 if (n->nlmsg_flags & NLM_F_EXCL)
1941 goto out;
1942 break;
1943 case RTM_DELTCLASS:
1944 err = tclass_del_notify(net, cops, skb, n, q, cl);
1945 /* Unbind the class with flilters with 0 */
1946 tc_bind_tclass(q, portid, clid, 0);
1947 goto out;
1948 case RTM_GETTCLASS:
1949 err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS);
1950 goto out;
1951 default:
1952 err = -EINVAL;
1953 goto out;
1954 }
1955 }
1956
1957 if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) {
1958 NL_SET_ERR_MSG(extack, "Shared blocks are not supported for classes");
1959 return -EOPNOTSUPP;
1960 }
1961
1962 new_cl = cl;
1963 err = -EOPNOTSUPP;
1964 if (cops->change)
1965 err = cops->change(q, clid, portid, tca, &new_cl, extack);
1966 if (err == 0) {
1967 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS);
1968 /* We just create a new class, need to do reverse binding. */
1969 if (cl != new_cl)
1970 tc_bind_tclass(q, portid, clid, new_cl);
1971 }
1972out:
1973 return err;
1974}
1975
1976struct qdisc_dump_args {
1977 struct qdisc_walker w;
1978 struct sk_buff *skb;
1979 struct netlink_callback *cb;
1980};
1981
1982static int qdisc_class_dump(struct Qdisc *q, unsigned long cl,
1983 struct qdisc_walker *arg)
1984{
1985 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
1986
1987 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid,
1988 a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
1989 RTM_NEWTCLASS);
1990}
1991
1992static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
1993 struct tcmsg *tcm, struct netlink_callback *cb,
1994 int *t_p, int s_t)
1995{
1996 struct qdisc_dump_args arg;
1997
1998 if (tc_qdisc_dump_ignore(q, false) ||
1999 *t_p < s_t || !q->ops->cl_ops ||
2000 (tcm->tcm_parent &&
2001 TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
2002 (*t_p)++;
2003 return 0;
2004 }
2005 if (*t_p > s_t)
2006 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
2007 arg.w.fn = qdisc_class_dump;
2008 arg.skb = skb;
2009 arg.cb = cb;
2010 arg.w.stop = 0;
2011 arg.w.skip = cb->args[1];
2012 arg.w.count = 0;
2013 q->ops->cl_ops->walk(q, &arg.w);
2014 cb->args[1] = arg.w.count;
2015 if (arg.w.stop)
2016 return -1;
2017 (*t_p)++;
2018 return 0;
2019}
2020
2021static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
2022 struct tcmsg *tcm, struct netlink_callback *cb,
2023 int *t_p, int s_t)
2024{
2025 struct Qdisc *q;
2026 int b;
2027
2028 if (!root)
2029 return 0;
2030
2031 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
2032 return -1;
2033
2034 if (!qdisc_dev(root))
2035 return 0;
2036
2037 if (tcm->tcm_parent) {
2038 q = qdisc_match_from_root(root, TC_H_MAJ(tcm->tcm_parent));
2039 if (q && tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
2040 return -1;
2041 return 0;
2042 }
2043 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
2044 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
2045 return -1;
2046 }
2047
2048 return 0;
2049}
2050
2051static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
2052{
2053 struct tcmsg *tcm = nlmsg_data(cb->nlh);
2054 struct net *net = sock_net(skb->sk);
2055 struct netdev_queue *dev_queue;
2056 struct net_device *dev;
2057 int t, s_t;
2058
2059 if (nlmsg_len(cb->nlh) < sizeof(*tcm))
2060 return 0;
2061 dev = dev_get_by_index(net, tcm->tcm_ifindex);
2062 if (!dev)
2063 return 0;
2064
2065 s_t = cb->args[0];
2066 t = 0;
2067
2068 if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0)
2069 goto done;
2070
2071 dev_queue = dev_ingress_queue(dev);
2072 if (dev_queue &&
2073 tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb,
2074 &t, s_t) < 0)
2075 goto done;
2076
2077done:
2078 cb->args[0] = t;
2079
2080 dev_put(dev);
2081 return skb->len;
2082}
2083
2084#ifdef CONFIG_PROC_FS
2085static int psched_show(struct seq_file *seq, void *v)
2086{
2087 seq_printf(seq, "%08x %08x %08x %08x\n",
2088 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
2089 1000000,
2090 (u32)NSEC_PER_SEC / hrtimer_resolution);
2091
2092 return 0;
2093}
2094
2095static int psched_open(struct inode *inode, struct file *file)
2096{
2097 return single_open(file, psched_show, NULL);
2098}
2099
2100static const struct file_operations psched_fops = {
2101 .open = psched_open,
2102 .read = seq_read,
2103 .llseek = seq_lseek,
2104 .release = single_release,
2105};
2106
2107static int __net_init psched_net_init(struct net *net)
2108{
2109 struct proc_dir_entry *e;
2110
2111 e = proc_create("psched", 0, net->proc_net, &psched_fops);
2112 if (e == NULL)
2113 return -ENOMEM;
2114
2115 return 0;
2116}
2117
2118static void __net_exit psched_net_exit(struct net *net)
2119{
2120 remove_proc_entry("psched", net->proc_net);
2121}
2122#else
2123static int __net_init psched_net_init(struct net *net)
2124{
2125 return 0;
2126}
2127
2128static void __net_exit psched_net_exit(struct net *net)
2129{
2130}
2131#endif
2132
2133static struct pernet_operations psched_net_ops = {
2134 .init = psched_net_init,
2135 .exit = psched_net_exit,
2136};
2137
2138static int __init pktsched_init(void)
2139{
2140 int err;
2141
2142 err = register_pernet_subsys(&psched_net_ops);
2143 if (err) {
2144 pr_err("pktsched_init: "
2145 "cannot initialize per netns operations\n");
2146 return err;
2147 }
2148
2149 register_qdisc(&pfifo_fast_ops);
2150 register_qdisc(&pfifo_qdisc_ops);
2151 register_qdisc(&bfifo_qdisc_ops);
2152 register_qdisc(&pfifo_head_drop_qdisc_ops);
2153 register_qdisc(&mq_qdisc_ops);
2154 register_qdisc(&noqueue_qdisc_ops);
2155
2156 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, 0);
2157 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, 0);
2158 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc,
2159 0);
2160 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, 0);
2161 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, 0);
2162 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass,
2163 0);
2164
2165 return 0;
2166}
2167
2168subsys_initcall(pktsched_init);